From 71c85e98944767145e4972e8193b4edf420bf936 Mon Sep 17 00:00:00 2001
From: DCCONSTRUCTIONS <dcconstructions@MacBook-Pro-DCCONSTRUCTIONS-2.local>
Date: Sun, 19 Jul 2026 01:07:21 +0300
Subject: [PATCH] feat(archive): complete recorded session lifecycle

---
 apps/control-station/src/App.tsx              |  25 +++-
 .../components/ObservationSessionSelect.tsx   |  91 ++++++++++----
 .../src/components/ObservationSources.tsx     |   8 +-
 .../src/components/RecordedFmp4Player.tsx     |  59 ++++------
 .../observation/recordedSessionAdmission.ts   |   8 +-
 .../src/core/observation/sessionArchive.ts    |  40 +++++++
 .../core/observation/useObservationLayout.ts  |  30 +++++
 .../observation/useObservationSessions.ts     |  90 +++++++-------
 .../src/styles/observation-sessions.css       |  37 ++++++
 .../src/workspaces/Workspaces.tsx             |  30 +++--
 .../test/observationSessions.test.mjs         |  66 +++++++++++
 .../test/recordedSessionAdmission.test.mjs    |   6 +-
 .../test/workspaceLayout.test.mjs             |  38 +++++-
 src/k1link/sessions/media.py                  |  32 ++++-
 src/k1link/sessions/preparation.py            | 104 ++++++++++++++--
 src/k1link/sessions/recording.py              |  24 ++++
 src/k1link/sessions/store.py                  |  68 ++++++++++-
 src/k1link/web/session_api.py                 |  73 ++++++++++++
 tests/test_session_api.py                     | 111 ++++++++++++++++++
 tests/test_session_preparation.py             |  35 ++++++
 tests/test_session_recording.py               |  19 +++
 tests/test_session_store.py                   |  72 ++++++++++++
 22 files changed, 922 insertions(+), 144 deletions(-)

diff --git a/apps/control-station/src/App.tsx b/apps/control-station/src/App.tsx
index 1684e44..a7a9be3 100644
--- a/apps/control-station/src/App.tsx
+++ b/apps/control-station/src/App.tsx
@@ -40,7 +40,10 @@ import {
 } from "./core/runtime/latestAsyncCommitter";
 import { useObservationLayout } from "./core/observation/useObservationLayout";
 import { recordedObservationSources } from "./core/observation/recordedObservationSources";
-import type { ObservationSessionReplayLaunch } from "./core/observation/sessionArchive";
+import type {
+  ObservationSessionReplayLaunch,
+  ObservationSessionSummary,
+} from "./core/observation/sessionArchive";
 import { useRecordedSessionAdmission } from "./core/observation/useRecordedSessionAdmission";
 import { useWorkspaceLayoutProfile } from "./core/observation/useWorkspaceLayoutProfile";
 import {
@@ -136,6 +139,7 @@ export default function App() {
   const [activeRoot, setActiveRoot] = useState<RootId | null>(null);
   const [sourceUrl, setSourceUrl] = useState("");
   const [recordedReplay, setRecordedReplay] = useState<ObservationSessionReplayLaunch | null>(null);
+  const [recordedReplayLabel, setRecordedReplayLabel] = useState<string | null>(null);
   const [replayTransitioning, setReplayTransitioning] = useState(false);
   const [sourceDraft, setSourceDraft] = useState("");
   const [sourceWindowOpen, setSourceWindowOpen] = useState(false);
@@ -447,6 +451,7 @@ export default function App() {
     // accepting the already-ready archive.
     setReplayTransitioning(true);
     setRecordedReplay(null);
+    setRecordedReplayLabel(null);
     setSourceUrl("");
     setSourceDraft("");
     await new Promise<void>((resolve) => {
@@ -454,11 +459,15 @@ export default function App() {
     });
   }, []);
 
-  const acceptRecordedReplay = useCallback((launch: ObservationSessionReplayLaunch) => {
+  const acceptRecordedReplay = useCallback((
+    session: ObservationSessionSummary,
+    launch: ObservationSessionReplayLaunch,
+  ) => {
     if (sourceSwitchBlockedRef.current) {
       throw new Error(SPATIAL_SOURCE_SWITCH_BLOCKED_REASON);
     }
     setRecordedReplay(launch);
+    setRecordedReplayLabel(session.label);
     setSourceUrl(launch.sourceUrl);
     setSourceDraft(launch.sourceUrl);
     setReplayTransitioning(false);
@@ -475,6 +484,7 @@ export default function App() {
     // switch, so it intentionally does not consult the acquisition guard.
     setReplayTransitioning(false);
     setRecordedReplay(null);
+    setRecordedReplayLabel(null);
     setSourceUrl("");
     setSourceDraft("");
   }, []);
@@ -634,7 +644,11 @@ export default function App() {
           <ApplicationPanel
             key={activeDefinition.id}
             eyebrow={activeDefinition.eyebrow}
-            title={activeDefinition.title}
+            title={
+              activeDefinition.kind === "spatial" && replayActive && recordedReplayLabel
+                ? `${activeDefinition.title}: ${recordedReplayLabel}`
+                : activeDefinition.title
+            }
             description={activeDefinition.description}
             expanded={workspace.contentExpanded}
             onExpandedChange={workspace.setContentExpanded}
@@ -646,11 +660,10 @@ export default function App() {
               ) : activeDefinition.kind === "spatial" ? (
                 <div className="observation-header-tools">
                   <ObservationSessionSelect
-                    limit={3}
                     disabled={runtime.pendingAction !== null || sourceSwitchBlocked}
                     blockedReason={sourceSwitchBlockedReason}
                     onReplayBegin={beginRecordedReplaySwitch}
-                    onReplayAccepted={(_session, launch) => acceptRecordedReplay(launch)}
+                    onReplayAccepted={acceptRecordedReplay}
                     onReplaySettled={(_session, outcome) => settleRecordedReplaySwitch(outcome)}
                   />
                   {layoutSaveNotice || workspaceLayoutProfile.error ? (
@@ -739,6 +752,7 @@ export default function App() {
                 setSourceDraft("");
                 setSourceUrl("");
                 setRecordedReplay(null);
+                setRecordedReplayLabel(null);
               }}
             >
               Сбросить адрес
@@ -752,6 +766,7 @@ export default function App() {
                 if (sourceSwitchBlockedRef.current) return;
                 setSourceUrl(sourceDraft.trim());
                 setRecordedReplay(null);
+                setRecordedReplayLabel(null);
               }}
             >
               Применить адрес
diff --git a/apps/control-station/src/components/ObservationSessionSelect.tsx b/apps/control-station/src/components/ObservationSessionSelect.tsx
index 440e1e4..9381606 100644
--- a/apps/control-station/src/components/ObservationSessionSelect.tsx
+++ b/apps/control-station/src/components/ObservationSessionSelect.tsx
@@ -1,4 +1,5 @@
-import { Dropdown, Icon } from "@nodedc/ui-react";
+import { useState } from "react";
+import { ConfirmationModal, Dropdown, Icon } from "@nodedc/ui-react";
 
 import {
   type ObservationSessionReplayLaunch,
@@ -93,7 +94,7 @@ function sessionDescription(session: ObservationSessionSummary): string {
 }
 
 export function ObservationSessionSelect({
-  limit = 3,
+  limit = 100,
   disabled = false,
   blockedReason = null,
   onReplayBegin,
@@ -116,6 +117,7 @@ export function ObservationSessionSelect({
     outcome: ObservationReplayOutcome,
   ) => void | Promise<void>;
 }) {
+  const [deleteTarget, setDeleteTarget] = useState<ObservationSessionSummary | null>(null);
   const sessions = useObservationSessions({
     limit,
     replayEnabled: blockedReason === null,
@@ -130,7 +132,7 @@ export function ObservationSessionSelect({
       : "Сохранённые сессии";
   const presentedTriggerCopy = blockedReason ?? triggerCopy;
 
-  return (
+  return <>
     <Dropdown
       className="observation-session-select"
       placement="bottom-end"
@@ -184,33 +186,48 @@ export function ObservationSessionSelect({
             <div className="observation-session-menu__list">
               {sessions.items.map((session) => {
                 const pending = sessions.replayingSessionId === session.id;
+                const deleting = sessions.deletingSessionId === session.id;
                 const failed = sessions.failedSessionId === session.id;
                 const visualState = observationSessionVisualState(session, { pending, failed });
                 return (
-                  <button
+                  <div
                     key={session.id}
-                    type="button"
-                    className="nodedc-dropdown-option observation-session-option"
-                    disabled={pending || !session.replayable}
-                    onClick={() => {
-                      void sessions.replay(session.id).then((accepted) => {
-                        if (accepted) close();
-                      });
-                    }}
+                    className="observation-session-option"
+                    data-deleting={deleting ? "true" : undefined}
                   >
-                    <span className="nodedc-dropdown-option__icon">
-                      <i data-session-visual-state={visualState} aria-hidden="true" />
-                    </span>
-                    <span className="nodedc-dropdown-option__body">
-                      <span className="nodedc-dropdown-option__label">{session.label}</span>
-                      <span className="nodedc-dropdown-option__description">
-                        {sessionDescription(session)}
+                    <button
+                      type="button"
+                      className="nodedc-dropdown-option observation-session-option__open"
+                      disabled={pending || deleting || !session.replayable}
+                      onClick={() => {
+                        void sessions.replay(session.id).then((accepted) => {
+                          if (accepted) close();
+                        });
+                      }}
+                    >
+                      <span className="nodedc-dropdown-option__icon">
+                        <i data-session-visual-state={visualState} aria-hidden="true" />
                       </span>
-                    </span>
-                    <span className="observation-session-option__state">
-                      {observationSessionVisualLabel(visualState)}
-                    </span>
-                  </button>
+                      <span className="nodedc-dropdown-option__body">
+                        <span className="nodedc-dropdown-option__label">{session.label}</span>
+                        <span className="nodedc-dropdown-option__description">
+                          {sessionDescription(session)}
+                        </span>
+                      </span>
+                      <span className="observation-session-option__state">
+                        {deleting ? "Удаление…" : observationSessionVisualLabel(visualState)}
+                      </span>
+                    </button>
+                    <button
+                      type="button"
+                      className="observation-session-option__delete"
+                      aria-label={`Удалить сохранённую сессию ${session.label}`}
+                      disabled={pending || deleting}
+                      onClick={() => setDeleteTarget(session)}
+                    >
+                      <Icon name="trash" size={15} />
+                    </button>
+                  </div>
                 );
               })}
             </div>
@@ -242,5 +259,29 @@ export function ObservationSessionSelect({
         </div>
       )}
     </Dropdown>
-  );
+    <ConfirmationModal
+      open={deleteTarget !== null}
+      title="Удалить сохранённую сессию?"
+      description={deleteTarget ? <>
+        <strong>{deleteTarget.label}</strong>
+        <p>
+          Сессия, исходные данные наблюдения, подготовленная Rerun-запись и
+          видеоматериалы будут удалены с этого сервера без возможности восстановления.
+        </p>
+        {sessions.error && sessions.deletingSessionId === null ? (
+          <p className="observation-session-delete-error" role="alert">{sessions.error}</p>
+        ) : null}
+      </> : null}
+      confirmLabel="Удалить сессию"
+      pendingLabel="Удаление…"
+      danger
+      onClose={() => {
+        if (sessions.deletingSessionId === null) setDeleteTarget(null);
+      }}
+      onConfirm={async () => {
+        if (!deleteTarget) return;
+        if (await sessions.remove(deleteTarget.id)) setDeleteTarget(null);
+      }}
+    />
+  </>;
 }
diff --git a/apps/control-station/src/components/ObservationSources.tsx b/apps/control-station/src/components/ObservationSources.tsx
index 89a29eb..21a3395 100644
--- a/apps/control-station/src/components/ObservationSources.tsx
+++ b/apps/control-station/src/components/ObservationSources.tsx
@@ -135,13 +135,17 @@ export function ObservationMedia({
   return (
     <div className="observation-media__empty">
       <Icon name={sourceIcon[source.modality]} size={20} />
-      <strong>{observationSourceStatusLabel(source)}</strong>
+      <strong>
+        {source.modality === "video" && source.activation && !source.activation.selected
+          ? "Источник отключён"
+          : observationSourceStatusLabel(source)}
+      </strong>
       <span>
         {source.modality === "video"
           ? source.activation?.controllable
             ? source.activation.selected
               ? "Повторите подключение — локальный адаптер перезапустит выбранную камеру"
-              : "Откройте канал — локальный адаптер подключит выбранную камеру"
+              : "Канал остановлен оператором; при необходимости его можно открыть снова"
             : "Канал известен, browser-preview сейчас недоступен"
           : source.description}
       </span>
diff --git a/apps/control-station/src/components/RecordedFmp4Player.tsx b/apps/control-station/src/components/RecordedFmp4Player.tsx
index 8192238..1e78b16 100644
--- a/apps/control-station/src/components/RecordedFmp4Player.tsx
+++ b/apps/control-station/src/components/RecordedFmp4Player.tsx
@@ -393,15 +393,27 @@ async function mountVerifiedRecordedEpoch(
   signal: AbortSignal,
 ): Promise<() => void> {
   const descriptor = epoch.descriptor;
-  if (
-    descriptor.mediaType === "video/mp4" ||
-    !globalThis.MediaSource ||
-    !MediaSource.isTypeSupported(descriptor.mediaType)
-  ) {
+  if (!descriptor.mediaType.startsWith("video/mp4;") || !video.canPlayType(descriptor.mediaType)) {
     throw new Error("Archived camera codec is not supported");
   }
-  const mediaSource = new MediaSource();
-  const objectUrl = URL.createObjectURL(mediaSource);
+  if (signal.aborted) throw new DOMException("Aborted", "AbortError");
+
+  // A sealed fragmented-MP4 generation is already complete and immutable.
+  // Present it as one Blob so Chromium can index and seek the whole archive
+  // without retaining the same 166+ MiB epoch in a quota-limited MSE
+  // SourceBuffer. Every constituent byte was fetched and SHA-256 verified
+  // before this boundary, and Blob preserves their canonical order.
+  const payload = new Blob([epoch.init, ...epoch.segments], {
+    type: descriptor.mediaType,
+  });
+  const expectedByteLength = epoch.init.byteLength + epoch.segments.reduce(
+    (total, segment) => total + segment.byteLength,
+    0,
+  );
+  if (payload.size !== expectedByteLength) {
+    throw new Error("Archived camera Blob is incomplete");
+  }
+  const objectUrl = URL.createObjectURL(payload);
   const cleanup = () => {
     video.pause();
     video.removeAttribute("src");
@@ -409,39 +421,8 @@ async function mountVerifiedRecordedEpoch(
     URL.revokeObjectURL(objectUrl);
   };
   video.src = objectUrl;
+  video.load();
   try {
-    await new Promise<void>((resolve, reject) => {
-      const onOpen = () => {
-        cleanupListeners();
-        resolve();
-      };
-      const onAbort = () => {
-        cleanupListeners();
-        reject(new DOMException("Aborted", "AbortError"));
-      };
-      const cleanupListeners = () => {
-        mediaSource.removeEventListener("sourceopen", onOpen);
-        signal.removeEventListener("abort", onAbort);
-      };
-      if (signal.aborted) {
-        onAbort();
-        return;
-      }
-      mediaSource.addEventListener("sourceopen", onOpen, { once: true });
-      signal.addEventListener("abort", onAbort, { once: true });
-    });
-    if (signal.aborted || mediaSource.readyState !== "open") {
-      throw new DOMException("Aborted", "AbortError");
-    }
-    const sourceBuffer = mediaSource.addSourceBuffer(descriptor.mediaType);
-    await appendRecordedMediaBuffer(sourceBuffer, epoch.init, signal);
-    for (const segment of epoch.segments) {
-      await appendRecordedMediaBuffer(sourceBuffer, segment, signal);
-    }
-    if (signal.aborted || mediaSource.readyState !== "open" || sourceBuffer.updating) {
-      throw new Error("Archived camera MediaSource closed before full append");
-    }
-    mediaSource.endOfStream();
     await waitForSeekableArchive(
       video,
       descriptor.timelineEndSeconds - descriptor.timelineStartSeconds,
diff --git a/apps/control-station/src/core/observation/recordedSessionAdmission.ts b/apps/control-station/src/core/observation/recordedSessionAdmission.ts
index e149bc1..c3c3e0b 100644
--- a/apps/control-station/src/core/observation/recordedSessionAdmission.ts
+++ b/apps/control-station/src/core/observation/recordedSessionAdmission.ts
@@ -1,9 +1,11 @@
 // A device-agnostic frontend safety policy. Sixteen channels covers multi-rig
 // vehicles while the independent byte/concurrency limits keep admission
-// bounded. OPFS-backed sealed generations are the planned scaling path beyond
-// this in-memory laboratory policy.
+// bounded. One real accepted archive is ~163 MiB for a single camera, so the
+// old 128 MiB laboratory ceiling rejected a valid sealed generation before the
+// first manifest request. OPFS-backed sealed generations remain the scaling
+// path beyond this in-memory policy.
 export const MAX_RECORDED_CAMERA_SOURCES = 16;
-export const MAX_RECORDED_MEDIA_SOURCE_BYTES = 128 * 1024 * 1024;
+export const MAX_RECORDED_MEDIA_SOURCE_BYTES = 256 * 1024 * 1024;
 export const MAX_RECORDED_SESSION_CAMERA_BYTES = 512 * 1024 * 1024;
 export const MAX_CONCURRENT_RECORDED_CAMERA_PREPARATIONS = 1;
 
diff --git a/apps/control-station/src/core/observation/sessionArchive.ts b/apps/control-station/src/core/observation/sessionArchive.ts
index fbc9656..009f26e 100644
--- a/apps/control-station/src/core/observation/sessionArchive.ts
+++ b/apps/control-station/src/core/observation/sessionArchive.ts
@@ -1110,6 +1110,46 @@ export async function fetchObservationSessionCatalog({
   return decodeObservationSessionCatalog(body);
 }
 
+export async function deleteObservationSession(
+  sessionId: string,
+  {
+    signal,
+    fetcher = globalThis.fetch,
+  }: { signal?: AbortSignal; fetcher?: ObservationSessionFetch } = {},
+): Promise<void> {
+  if (!SAFE_ID.test(sessionId)) {
+    throw new ObservationSessionContractError(
+      "Идентификатор удаляемой сессии имеет недопустимый формат.",
+    );
+  }
+  let response: Response;
+  try {
+    response = await fetcher(
+      `/api/v1/observation-sessions/${encodeURIComponent(sessionId)}`,
+      {
+        method: "DELETE",
+        headers: { Accept: "application/json" },
+        signal,
+      },
+    );
+  } catch (error) {
+    if (error instanceof DOMException && error.name === "AbortError") throw error;
+    throw new ObservationSessionApiError("Не удалось удалить сохранённую сессию.");
+  }
+  const body = await responseBody(response);
+  if (!response.ok || response.status !== 204) {
+    throw new ObservationSessionApiError(
+      apiErrorMessage(body, `Удаление сессии вернуло HTTP ${response.status}.`),
+      response.status,
+    );
+  }
+  if (body !== undefined) {
+    throw new ObservationSessionContractError(
+      "Сервер вернул данные после подтверждённого удаления сессии.",
+    );
+  }
+}
+
 export async function replayObservationSession(
   sessionId: string,
   {
diff --git a/apps/control-station/src/core/observation/useObservationLayout.ts b/apps/control-station/src/core/observation/useObservationLayout.ts
index d82c256..64ea7cc 100644
--- a/apps/control-station/src/core/observation/useObservationLayout.ts
+++ b/apps/control-station/src/core/observation/useObservationLayout.ts
@@ -27,6 +27,18 @@ export function observationPresentationSourceAfterLayoutApply(
   return mode === "preserve" ? currentSourceId : null;
 }
 
+export function visibleSourceIdsAfterRecordedCatalogActivation(
+  currentIds: readonly string[],
+  sources: readonly ObservationSourceDescriptor[],
+): string[] {
+  let visibleIds = [...currentIds];
+  for (const source of sources) {
+    if (source.transport !== "recording" || !canOpenByDefault(source)) continue;
+    visibleIds = openObservationSource(visibleIds, source.id, sources).visibleIds;
+  }
+  return visibleIds;
+}
+
 export interface ObservationLayoutController {
   visibleSourceIds: ReadonlySet<string>;
   focusedSourceId: string | null;
@@ -230,7 +242,25 @@ export function useObservationLayout(
     }
     const desired = desiredSnapshotRef.current;
     if (desired) {
+      const previousIdentity = initializedCatalog.current;
       initializedCatalog.current = identity;
+      if (
+        previousIdentity !== identity &&
+        sources.some((source) => source.transport === "recording")
+      ) {
+        const nextVisible = visibleSourceIdsAfterRecordedCatalogActivation(
+          visibleIdsRef.current,
+          sources,
+        );
+        commitVisibleIds(nextVisible);
+        const firstRecordedOverlay = sources.find((source) => (
+          source.transport === "recording" &&
+          source.capabilities.overlay &&
+          nextVisible.includes(source.id)
+        ));
+        commitActiveFloatingSourceId(firstRecordedOverlay?.id ?? null);
+        persistLiveLayout();
+      }
       return;
     }
     if (initializedCatalog.current === identity) return;
diff --git a/apps/control-station/src/core/observation/useObservationSessions.ts b/apps/control-station/src/core/observation/useObservationSessions.ts
index 9b795a4..adbd0bc 100644
--- a/apps/control-station/src/core/observation/useObservationSessions.ts
+++ b/apps/control-station/src/core/observation/useObservationSessions.ts
@@ -2,6 +2,7 @@ import { useCallback, useEffect, useRef, useState } from "react";
 
 import {
   decodeObservationSessionPreparation,
+  deleteObservationSession,
   fetchObservationSessionCatalog,
   fetchObservationSessionPreparation,
   replayObservationSession,
@@ -32,9 +33,11 @@ export interface ObservationSessionsController {
   preparation: ObservationSessionPreparation | null;
   replayProgress: ObservationReplayProgress | null;
   failedSessionId: string | null;
+  deletingSessionId: string | null;
   refresh: () => Promise<boolean>;
   replay: (sessionId: string) => Promise<boolean>;
   retry: () => Promise<boolean>;
+  remove: (sessionId: string) => Promise<boolean>;
 }
 
 export interface ObservationReplayAttempt {
@@ -360,7 +363,7 @@ export function clearObservationReplayPreparation(
 }
 
 export function useObservationSessions({
-  limit = 3,
+  limit = 100,
   replayEnabled = true,
   onReplayBegin,
   onReplayAccepted,
@@ -389,12 +392,12 @@ export function useObservationSessions({
   const [preparation, setPreparation] = useState<ObservationSessionPreparation | null>(null);
   const [replayProgress, setReplayProgress] = useState<ObservationReplayProgress | null>(null);
   const [failedSessionId, setFailedSessionId] = useState<string | null>(null);
+  const [deletingSessionId, setDeletingSessionId] = useState<string | null>(null);
   const mounted = useRef(true);
   const catalogSequence = useRef(0);
   const reattachStarted = useRef(false);
   const replayEnabledRef = useRef(replayEnabled);
   replayEnabledRef.current = replayEnabled;
-  const preparationPollSequence = useRef(0);
   const replayCoordinator = useRef<ObservationReplayCoordinator | null>(null);
   if (replayCoordinator.current === null) {
     replayCoordinator.current = createObservationReplayCoordinator();
@@ -409,26 +412,30 @@ export function useObservationSessions({
     setReplayingSessionId(null);
     setReplayProgress(null);
   }, [replayEnabled]);
-  const safeLimit = Number.isFinite(limit) ? Math.max(0, Math.floor(limit)) : 3;
+  const safeLimit = Number.isFinite(limit)
+    ? Math.min(100, Math.max(1, Math.floor(limit)))
+    : 100;
 
-  const refresh = useCallback(async () => {
+  const loadCatalog = useCallback(async (foreground: boolean) => {
     const sequence = ++catalogSequence.current;
-    setState("loading");
-    setError(null);
+    if (foreground) setState("loading");
     try {
       const catalog = await fetchObservationSessionCatalog({ limit: safeLimit });
       if (!mounted.current || sequence !== catalogSequence.current) return false;
       setItems(catalog.items.slice(0, safeLimit));
       setState("ready");
+      setError(null);
       return true;
     } catch (loadError) {
       if (!mounted.current || sequence !== catalogSequence.current) return false;
-      setState("error");
+      if (foreground) setState("error");
       setError(errorMessage(loadError));
       return false;
     }
   }, [safeLimit]);
 
+  const refresh = useCallback(() => loadCatalog(true), [loadCatalog]);
+
   useEffect(() => {
     mounted.current = true;
     void refresh();
@@ -439,44 +446,21 @@ export function useObservationSessions({
     };
   }, [refresh]);
 
-  const catalogHasActivePreparation = items.some((item) => (
-    item.preparation !== null &&
-    ["queued", "validating", "exporting", "finalizing"].includes(item.preparation.state)
-  ));
-
   useEffect(() => {
-    if (state !== "ready" || !catalogHasActivePreparation) return;
-    const sequence = ++preparationPollSequence.current;
-    const controller = new AbortController();
-    const timer = window.setTimeout(async () => {
-      try {
-        const catalog = await fetchObservationSessionCatalog({
-          limit: safeLimit,
-          signal: controller.signal,
-        });
-        if (
-          mounted.current &&
-          !controller.signal.aborted &&
-          sequence === preparationPollSequence.current
-        ) {
-          setItems(catalog.items.slice(0, safeLimit));
-        }
-      } catch (pollError) {
-        if (
-          mounted.current &&
-          !controller.signal.aborted &&
-          sequence === preparationPollSequence.current
-        ) {
-          setError(errorMessage(pollError));
-        }
-      }
-    }, 1_500);
-    return () => {
-      preparationPollSequence.current += 1;
-      window.clearTimeout(timer);
-      controller.abort();
+    if (state !== "ready") return;
+    let disposed = false;
+    let timer = 0;
+    const poll = async () => {
+      if (disposed) return;
+      await loadCatalog(false);
+      if (!disposed) timer = window.setTimeout(() => void poll(), 2_000);
     };
-  }, [catalogHasActivePreparation, items, safeLimit, state]);
+    timer = window.setTimeout(() => void poll(), 2_000);
+    return () => {
+      disposed = true;
+      window.clearTimeout(timer);
+    };
+  }, [loadCatalog, state]);
 
   const executeReplay = useCallback(async (
     session: ObservationSessionSummary,
@@ -606,6 +590,24 @@ export function useObservationSessions({
     return replay(failedSessionId);
   }, [failedSessionId, replay]);
 
+  const remove = useCallback(async (sessionId: string) => {
+    if (deletingSessionId !== null || replayingSessionId === sessionId) return false;
+    setDeletingSessionId(sessionId);
+    setError(null);
+    try {
+      await deleteObservationSession(sessionId);
+      if (!mounted.current) return false;
+      setItems((current) => current.filter((item) => item.id !== sessionId));
+      setFailedSessionId((current) => current === sessionId ? null : current);
+      return true;
+    } catch (deleteError) {
+      if (mounted.current) setError(errorMessage(deleteError));
+      return false;
+    } finally {
+      if (mounted.current) setDeletingSessionId(null);
+    }
+  }, [deletingSessionId, replayingSessionId]);
+
   return {
     items,
     state,
@@ -614,8 +616,10 @@ export function useObservationSessions({
     preparation,
     replayProgress,
     failedSessionId,
+    deletingSessionId,
     refresh,
     replay,
     retry,
+    remove,
   };
 }
diff --git a/apps/control-station/src/styles/observation-sessions.css b/apps/control-station/src/styles/observation-sessions.css
index 239c889..421a805 100644
--- a/apps/control-station/src/styles/observation-sessions.css
+++ b/apps/control-station/src/styles/observation-sessions.css
@@ -117,9 +117,42 @@
 }
 
 .observation-session-option {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) 2.35rem;
+  align-items: stretch;
+  gap: 0.2rem;
+}
+
+.observation-session-option__open {
+  width: 100%;
+  min-width: 0;
   grid-template-columns: auto minmax(0, 1fr) auto;
 }
 
+.observation-session-option__delete {
+  display: grid;
+  min-width: 2.35rem;
+  place-items: center;
+  border: 0;
+  border-radius: 0;
+  background: transparent;
+  color: var(--nodedc-text-muted);
+  cursor: pointer;
+}
+
+.observation-session-option__delete:hover:not(:disabled),
+.observation-session-option__delete:focus-visible {
+  background: transparent;
+  color: rgb(var(--nodedc-danger-rgb));
+  outline: none;
+}
+
+.observation-session-option__delete:disabled,
+.observation-session-option[data-deleting="true"] {
+  opacity: 0.55;
+  cursor: default;
+}
+
 .observation-session-option i {
   display: block;
   width: 0.45rem;
@@ -217,6 +250,10 @@
   cursor: pointer;
 }
 
+.observation-session-delete-error {
+  color: rgb(var(--nodedc-danger-rgb));
+}
+
 @media (max-width: 860px) {
   .workspace-layout-feedback {
     display: none;
diff --git a/apps/control-station/src/workspaces/Workspaces.tsx b/apps/control-station/src/workspaces/Workspaces.tsx
index ab33a1c..d5f7557 100644
--- a/apps/control-station/src/workspaces/Workspaces.tsx
+++ b/apps/control-station/src/workspaces/Workspaces.tsx
@@ -323,11 +323,19 @@ function SpatialWorkspace({
   const floatingSourceMaximized = Boolean(observationLayout.maximizedFloatingSourceId);
   const timeline = state?.observationTimeline;
   const viewportRef = useRef<HTMLDivElement>(null);
-  const presentedViewerStatus = rerunPresentationStatus(
-    viewerStatus,
-    recordedSessionGate,
-    recordedSource,
-  );
+  const intentionalSourceEnd = !recordedSource && [
+    "awaiting_external_stop",
+    "stopping",
+    "finalizing",
+    "completed",
+  ].includes(state?.acquisition?.state ?? "");
+  const presentedViewerStatus = intentionalSourceEnd
+    ? "idle"
+    : rerunPresentationStatus(
+        viewerStatus,
+        recordedSessionGate,
+        recordedSource,
+      );
 
   const onStatusChange = useCallback((status: RerunViewportStatus, message?: string) => {
     setViewerStatus(status);
@@ -389,7 +397,7 @@ function SpatialWorkspace({
   }, [observationLayout.setViewportSize]);
 
   const viewerStatusLabel = {
-    idle: "Источник не назначен",
+    idle: intentionalSourceEnd ? "Источник отключён" : "Источник не назначен",
     loading: "Подключение",
     ready: "Визуализатор готов",
     error: "Ошибка источника",
@@ -500,7 +508,7 @@ function SpatialWorkspace({
           >
             <span className="section-eyebrow">ВИЗУАЛЬНЫЙ ДВИЖОК</span>
             <StatusBadge tone={viewerStatusTone}>{viewerStatusLabel}</StatusBadge>
-            {viewerMessage ? <small>{viewerMessage}</small> : null}
+            {!intentionalSourceEnd && viewerMessage ? <small>{viewerMessage}</small> : null}
           </div>
 
           <div
@@ -679,6 +687,7 @@ function CameraSourceCard({
         : selectedPeer
           ? "Переключить"
           : "Открыть канал";
+  const sourceDisconnected = Boolean(source.activation && !source.activation.selected && visible);
 
   return (
     <article className="camera-slot" data-focused={focused ? "true" : undefined}>
@@ -686,8 +695,11 @@ function CameraSourceCard({
         <span>{source.label}</span>
         <div className="camera-slot__head-actions">
           <span className="camera-slot__status">
-            <i data-availability={source.availability} aria-hidden="true" />
-            {observationSourceStatusLabel(source)}
+            <i
+              data-availability={sourceDisconnected ? "unverified" : source.availability}
+              aria-hidden="true"
+            />
+            {sourceDisconnected ? "Источник отключён" : observationSourceStatusLabel(source)}
           </span>
           {source.activation && !focused ? (
             <button
diff --git a/apps/control-station/test/observationSessions.test.mjs b/apps/control-station/test/observationSessions.test.mjs
index 4039ef3..d9498b4 100644
--- a/apps/control-station/test/observationSessions.test.mjs
+++ b/apps/control-station/test/observationSessions.test.mjs
@@ -9,6 +9,7 @@ let decodeObservationSessionCatalog;
 let decodeObservationSessionReplay;
 let decodeObservationSessionPreparation;
 let fetchObservationSessionCatalog;
+let deleteObservationSession;
 let replayObservationSession;
 let fetchObservationSessionPreparation;
 let cancelObservationSessionPreparation;
@@ -34,6 +35,7 @@ before(async () => {
     decodeObservationSessionReplay,
     decodeObservationSessionPreparation,
     fetchObservationSessionCatalog,
+    deleteObservationSession,
     replayObservationSession,
     fetchObservationSessionPreparation,
     cancelObservationSessionPreparation,
@@ -136,6 +138,39 @@ test("session catalog decodes canonical snake_case into a path-free camelCase mo
   assert.equal("path" in catalog.items[0], false);
 });
 
+test("opened archive is named in the scene header and trash hover has no pill", async () => {
+  const appSource = await readFile(new URL("../src/App.tsx", import.meta.url), "utf8");
+  const styles = await readFile(
+    new URL("../src/styles/observation-sessions.css", import.meta.url),
+    "utf8",
+  );
+  const spatialControls = await readFile(
+    new URL(
+      "../../../plugins/xgrids-k1/frontend/src/components/K1SpatialControls.tsx",
+      import.meta.url,
+    ),
+    "utf8",
+  );
+  const acquisitionPipeline = await readFile(
+    new URL(
+      "../../../plugins/xgrids-k1/frontend/src/components/K1AcquisitionPipeline.tsx",
+      import.meta.url,
+    ),
+    "utf8",
+  );
+
+  assert.match(appSource, /setRecordedReplayLabel\(session\.label\)/);
+  assert.match(appSource, /`\$\{activeDefinition\.title\}: \$\{recordedReplayLabel\}`/);
+  const deleteStyle = styles.slice(
+    styles.indexOf(".observation-session-option__delete"),
+    styles.indexOf(".observation-session-option__delete:disabled"),
+  );
+  assert.match(deleteStyle, /background:\s*transparent/);
+  assert.doesNotMatch(deleteStyle, /danger-rgb\) \/ 0\.12/);
+  assert.doesNotMatch(spatialControls, /Индикатор постоянно зелёный/);
+  assert.doesNotMatch(acquisitionPipeline, /Индикатор постоянно зелёный/);
+});
+
 test("session catalog exposes authoritative background preparation state", () => {
   const catalog = decodeObservationSessionCatalog({
     items: [session({
@@ -302,6 +337,37 @@ test("catalog API preserves HTTP detail without accepting a malformed success bo
   );
 });
 
+test("delete API uses one opaque same-origin target and requires an empty 204", async () => {
+  const calls = [];
+  await deleteObservationSession("session-20260716T205632Z", {
+    fetcher: async (input, init) => {
+      calls.push({ input: String(input), init });
+      return new Response(null, { status: 204 });
+    },
+  });
+
+  assert.equal(calls.length, 1);
+  assert.equal(
+    calls[0].input,
+    "/api/v1/observation-sessions/session-20260716T205632Z",
+  );
+  assert.equal(calls[0].init.method, "DELETE");
+  await assert.rejects(
+    deleteObservationSession("../private", { fetcher: async () => new Response(null) }),
+    ObservationSessionContractError,
+  );
+  await assert.rejects(
+    deleteObservationSession("session-20260716T205632Z", {
+      fetcher: async () => new Response(JSON.stringify({ detail: "recording is open" }), {
+        status: 409,
+        headers: { "Content-Type": "application/json" },
+      }),
+    }),
+    (error) => error instanceof ObservationSessionApiError &&
+      error.status === 409 && error.message === "recording is open",
+  );
+});
+
 test("replay API accepts only a same-origin seekable recording descriptor", async () => {
   const calls = [];
   const launch = await replayObservationSession("session-20260716T205632Z", {
diff --git a/apps/control-station/test/recordedSessionAdmission.test.mjs b/apps/control-station/test/recordedSessionAdmission.test.mjs
index 2bc4ae9..1ee5aa6 100644
--- a/apps/control-station/test/recordedSessionAdmission.test.mjs
+++ b/apps/control-station/test/recordedSessionAdmission.test.mjs
@@ -78,7 +78,7 @@ test("any RRD or camera failure closes the complete recorded session", () => {
   );
 });
 
-test("camera admission enforces independent 16/128/512 MiB limits before fetching", () => {
+test("camera admission enforces independent 16/256/512 MiB limits before fetching", () => {
   const {
     MAX_RECORDED_CAMERA_SOURCES,
     MAX_RECORDED_MEDIA_SOURCE_BYTES,
@@ -86,10 +86,10 @@ test("camera admission enforces independent 16/128/512 MiB limits before fetchin
     recordedCameraDescriptorPreflight,
   } = admission;
   assert.equal(MAX_RECORDED_CAMERA_SOURCES, 16);
-  assert.equal(MAX_RECORDED_MEDIA_SOURCE_BYTES, 128 * 1024 * 1024);
+  assert.equal(MAX_RECORDED_MEDIA_SOURCE_BYTES, 256 * 1024 * 1024);
   assert.equal(MAX_RECORDED_SESSION_CAMERA_BYTES, 512 * 1024 * 1024);
   assert.equal(recordedCameraDescriptorPreflight(
-    Array.from({ length: 4 }, (_, index) => ({
+    Array.from({ length: 2 }, (_, index) => ({
       id: `camera.${index}`,
       byteLength: MAX_RECORDED_MEDIA_SOURCE_BYTES,
     })),
diff --git a/apps/control-station/test/workspaceLayout.test.mjs b/apps/control-station/test/workspaceLayout.test.mjs
index fca7559..a62aefd 100644
--- a/apps/control-station/test/workspaceLayout.test.mjs
+++ b/apps/control-station/test/workspaceLayout.test.mjs
@@ -14,6 +14,7 @@ let saveObservationWorkspaceLayoutProfile;
 let WorkspaceLayoutApiError;
 let WorkspaceLayoutContractError;
 let observationPresentationSourceAfterLayoutApply;
+let visibleSourceIdsAfterRecordedCatalogActivation;
 
 before(async () => {
   server = await createServer({
@@ -31,9 +32,10 @@ before(async () => {
     WorkspaceLayoutApiError,
     WorkspaceLayoutContractError,
   } = await server.ssrLoadModule("/src/core/observation/workspaceLayout.ts"));
-  ({ observationPresentationSourceAfterLayoutApply } = await server.ssrLoadModule(
-    "/src/core/observation/useObservationLayout.ts",
-  ));
+  ({
+    observationPresentationSourceAfterLayoutApply,
+    visibleSourceIdsAfterRecordedCatalogActivation,
+  } = await server.ssrLoadModule("/src/core/observation/useObservationLayout.ts"));
 });
 
 after(async () => {
@@ -181,6 +183,36 @@ test("fullscreen presentation survives the viewport resize it causes", () => {
   );
 });
 
+test("opening a recorded catalog reveals its sealed cameras beside the point cloud", () => {
+  const source = (id, modality, transport = "recording") => ({
+    id,
+    modality,
+    transport,
+    availability: "available",
+    previewUrl: null,
+    delivery: modality === "video" ? { kind: "recorded-fmp4-manifest" } : null,
+    activation: null,
+    capabilities: {
+      defaultVisible: true,
+      overlay: modality === "video",
+    },
+  });
+  const sources = [
+    source("recorded.spatial.primary", "point-cloud"),
+    source("recorded.camera.left", "video"),
+    source("recorded.camera.right", "video"),
+    source("live.camera", "video", "websocket"),
+  ];
+
+  assert.deepEqual(
+    visibleSourceIdsAfterRecordedCatalogActivation(
+      ["recorded.spatial.primary"],
+      sources,
+    ),
+    ["recorded.spatial.primary", "recorded.camera.left", "recorded.camera.right"],
+  );
+});
+
 test("workspace layout API uses the canonical endpoint and optimistic revision", async () => {
   const calls = [];
   const current = decodeObservationWorkspaceLayoutProfile(wireProfile());
diff --git a/src/k1link/sessions/media.py b/src/k1link/sessions/media.py
index 780a029..4b4301f 100644
--- a/src/k1link/sessions/media.py
+++ b/src/k1link/sessions/media.py
@@ -8,7 +8,7 @@ import re
 import secrets
 import stat
 import threading
-from collections.abc import Iterator
+from collections.abc import Iterable, Iterator
 from contextlib import suppress
 from dataclasses import dataclass
 from pathlib import Path
@@ -175,6 +175,36 @@ class RecordedMediaInspector:
             self._cache[key] = _CachedManifest(identity=identity, manifest=manifest)
         return manifest
 
+    def delete_prepared(self, session_id: str, artifact_ids: Iterable[str]) -> None:
+        """Forget and remove path-free preparation sidecars for one session."""
+
+        unique_artifact_ids = tuple(dict.fromkeys(artifact_ids))
+        with self._lock:
+            for artifact_id in unique_artifact_ids:
+                self._cache.pop((session_id, artifact_id), None)
+        if self._cache_root is None:
+            return
+        for artifact_id in unique_artifact_ids:
+            sidecar = self._cache_root / _sidecar_name(session_id, artifact_id)
+            try:
+                metadata = sidecar.lstat()
+            except FileNotFoundError:
+                continue
+            except OSError as exc:
+                raise SessionIntegrityError(
+                    "recorded media preparation could not be inspected"
+                ) from exc
+            if stat.S_ISLNK(metadata.st_mode) or not stat.S_ISREG(metadata.st_mode):
+                raise SessionIntegrityError(
+                    "recorded media preparation is not a regular file"
+                )
+            try:
+                sidecar.unlink()
+            except OSError as exc:
+                raise SessionIntegrityError(
+                    "recorded media preparation could not be deleted"
+                ) from exc
+
     def restore_prepared(
         self,
         artifact: RecordedMediaArtifact,
diff --git a/src/k1link/sessions/preparation.py b/src/k1link/sessions/preparation.py
index 990b738..0ae0dce 100644
--- a/src/k1link/sessions/preparation.py
+++ b/src/k1link/sessions/preparation.py
@@ -87,6 +87,13 @@ class _WorkerGeneration:
     worker: threading.Thread | None = None
 
 
+@dataclass(slots=True)
+class _LaunchReservation:
+    preparation_id: str
+    release: Callable[[], None]
+    timer: threading.Timer
+
+
 class SessionRecordingPreparationManager:
     """One bounded, process-owned conversion worker for durable recordings.
 
@@ -131,6 +138,7 @@ class SessionRecordingPreparationManager:
         self._ready_restorer = ready_restorer
         self._guard = threading.RLock()
         self._current_by_session: dict[str, _PreparationJob] = {}
+        self._launch_reservations: dict[str, _LaunchReservation] = {}
         self._closed = True
         self._generation_counter = 0
         self._active_generation: _WorkerGeneration | None = None
@@ -379,10 +387,7 @@ class SessionRecordingPreparationManager:
         if pinned is None:
             return None
         snapshot, release = pinned
-        timer = threading.Timer(lease_seconds, release)
-        timer.name = f"missioncore-recording-launch-lease-{snapshot.preparation_id}"
-        timer.daemon = True
-        timer.start()
+        self._reserve_launch_lease(snapshot, release, lease_seconds)
         return snapshot
 
     def pin_ready(
@@ -393,6 +398,7 @@ class SessionRecordingPreparationManager:
     ) -> tuple[RecordingPreparationSnapshot, Callable[[], None]] | None:
         """Cheaply lease the exact already-validated ready generation."""
 
+        launch_release: Callable[[], None] | None = None
         with self._guard:
             job = self._current_by_session.get(session_id)
             if (
@@ -409,7 +415,17 @@ class SessionRecordingPreparationManager:
                     self._current_by_session.pop(session_id, None)
                 return None
             snapshot = self._snapshot_locked(job)
-            return snapshot, pinned
+            reservation = self._launch_reservations.get(session_id)
+            if (
+                reservation is not None
+                and reservation.preparation_id == snapshot.preparation_id
+            ):
+                self._launch_reservations.pop(session_id, None)
+                reservation.timer.cancel()
+                launch_release = reservation.release
+        if launch_release is not None:
+            launch_release()
+        return snapshot, pinned
 
     def reserve_ready(
         self,
@@ -426,12 +442,26 @@ class SessionRecordingPreparationManager:
         if pinned is None:
             return None
         snapshot, release = pinned
-        timer = threading.Timer(lease_seconds, release)
-        timer.name = f"missioncore-recording-launch-lease-{snapshot.preparation_id}"
-        timer.daemon = True
-        timer.start()
+        self._reserve_launch_lease(snapshot, release, lease_seconds)
         return snapshot
 
+    def release_launch_reservation(self, session_id: str) -> bool:
+        """Release an unused launch-to-GET lease for one session.
+
+        The first matching recording GET consumes this reservation after it
+        acquires its own response-lifetime pin. Deletion may release a launch
+        reservation that was never consumed; an active response pin remains
+        independently protected by the materializer.
+        """
+
+        with self._guard:
+            reservation = self._launch_reservations.pop(session_id, None)
+            if reservation is None:
+                return False
+            reservation.timer.cancel()
+        reservation.release()
+        return True
+
     def cancel(self, session_id: str, *, preparation_id: str | None = None) -> bool:
         with self._guard:
             job = self._current_by_session.get(session_id)
@@ -447,11 +477,30 @@ class SessionRecordingPreparationManager:
                 self._transition_locked(job, "cancelled", job.progress)
             return True
 
+    def discard(self, session_id: str) -> bool:
+        """Forget one non-active job before its source session is deleted."""
+
+        with self._guard:
+            job = self._current_by_session.get(session_id)
+            if job is not None and job.state in ACTIVE_PREPARATION_STATES:
+                return False
+            self._current_by_session.pop(session_id, None)
+            reservation = self._launch_reservations.pop(session_id, None)
+            if reservation is not None:
+                reservation.timer.cancel()
+        if reservation is not None:
+            reservation.release()
+        return True
+
     def close(self, *, timeout: float = 5.0) -> None:
         with self._guard:
             if self._closed:
                 return
             self._closed = True
+            reservations = tuple(self._launch_reservations.values())
+            self._launch_reservations.clear()
+            for reservation in reservations:
+                reservation.timer.cancel()
             for job in self._current_by_session.values():
                 if job.state in ACTIVE_PREPARATION_STATES:
                     job.interrupted_by_restart = not job.cancelled_by_operator
@@ -466,9 +515,46 @@ class SessionRecordingPreparationManager:
                 pending.stop_event.set()
                 self._pending_generation = None
             worker = None if active is None else active.worker
+        for reservation in reservations:
+            reservation.release()
         if worker is not None:
             worker.join(timeout=max(0.0, timeout))
 
+    def _reserve_launch_lease(
+        self,
+        snapshot: RecordingPreparationSnapshot,
+        release: Callable[[], None],
+        lease_seconds: float,
+    ) -> None:
+        timer = threading.Timer(
+            lease_seconds,
+            self._expire_launch_reservation,
+            args=(snapshot.session_id, snapshot.preparation_id),
+        )
+        timer.name = f"missioncore-recording-launch-lease-{snapshot.preparation_id}"
+        timer.daemon = True
+        reservation = _LaunchReservation(
+            preparation_id=snapshot.preparation_id,
+            release=release,
+            timer=timer,
+        )
+        with self._guard:
+            previous = self._launch_reservations.pop(snapshot.session_id, None)
+            if previous is not None:
+                previous.timer.cancel()
+            self._launch_reservations[snapshot.session_id] = reservation
+        if previous is not None:
+            previous.release()
+        timer.start()
+
+    def _expire_launch_reservation(self, session_id: str, preparation_id: str) -> None:
+        with self._guard:
+            reservation = self._launch_reservations.get(session_id)
+            if reservation is None or reservation.preparation_id != preparation_id:
+                return
+            self._launch_reservations.pop(session_id, None)
+        reservation.release()
+
     def _run_generation(self, generation: _WorkerGeneration) -> None:
         work_queue = generation.work_queue
         try:
diff --git a/src/k1link/sessions/recording.py b/src/k1link/sessions/recording.py
index 6c04eb5..97d6d99 100644
--- a/src/k1link/sessions/recording.py
+++ b/src/k1link/sessions/recording.py
@@ -218,6 +218,30 @@ class SessionRecordingMaterializer:
             self._increment_pin_locked(recording.session_id)
         return self._release_callback(recording.session_id)
 
+    def delete_cached(self, session_id: str) -> bool:
+        """Delete one exact derived RRD cache unless a response still leases it."""
+
+        if SESSION_ID_PATTERN.fullmatch(session_id) is None:
+            raise ValueError("recording cache session id is invalid")
+        with self._lock_for(session_id), self._cache_guard:
+            if self._pinned_sessions.get(session_id, 0) > 0:
+                return False
+            session_root = self.recordings_root / session_id
+            if session_root.exists() or session_root.is_symlink():
+                metadata = session_root.lstat()
+                if stat.S_ISLNK(metadata.st_mode) or not stat.S_ISDIR(metadata.st_mode):
+                    raise RecordingMaterializationError(
+                        "session recording cache is not a real directory"
+                    )
+                if session_root.parent.resolve(strict=True) != self.recordings_root:
+                    raise RecordingMaterializationError(
+                        "session recording cache escapes the private data root"
+                    )
+                shutil.rmtree(session_root)
+            with self._memory_guard:
+                self._validated_memory.pop(session_id, None)
+            return True
+
     def __call__(self, command: ReplayCommand) -> MaterializedRecording:
         """Alias for :meth:`materialize`, suitable for the web API protocol."""
 
diff --git a/src/k1link/sessions/store.py b/src/k1link/sessions/store.py
index 7affb1b..1d887d0 100644
--- a/src/k1link/sessions/store.py
+++ b/src/k1link/sessions/store.py
@@ -3,12 +3,15 @@ from __future__ import annotations
 import json
 import os
 import re
+import shutil
 import sqlite3
+import stat
 import threading
 from collections.abc import Iterator
 from contextlib import contextmanager
 from pathlib import Path
 from typing import Any, cast
+from uuid import uuid4
 
 from k1link.artifacts import utc_now_iso
 
@@ -142,11 +145,18 @@ class SessionStore:
         candidates = source.discover(allowed_root)
         imported: list[str] = []
         for candidate in candidates:
-            self._upsert_candidate(source, candidate)
+            try:
+                self._upsert_candidate(source, candidate)
+            except SessionIntegrityError:
+                # One incomplete/corrupt evidence directory must not starve a
+                # later valid session in the same plugin archive. Keep any
+                # previously indexed row because the candidate is still
+                # physically present, but never admit its current artifacts.
+                continue
             imported.append(candidate.session_id)
         with self._lock, self._connect() as connection:
             connection.execute("BEGIN IMMEDIATE")
-            discovered = set(imported)
+            discovered = {candidate.session_id for candidate in candidates}
             indexed = connection.execute(
                 "SELECT session_id FROM observation_sessions "
                 "WHERE plugin_id = ? AND archive_id = ? AND allowed_root = ?",
@@ -232,6 +242,60 @@ class SessionStore:
         )
         return SessionDetail(summary=_summary_from_row(row), sources=sources, artifacts=artifacts)
 
+    def delete_session(self, session_id: str) -> None:
+        """Permanently delete one exact catalogued evidence directory and row."""
+
+        _validate_identifier(session_id, "session id")
+        with self._lock:
+            with self._connect() as connection:
+                row = connection.execute(
+                    "SELECT allowed_root, session_root FROM observation_sessions "
+                    "WHERE session_id = ?",
+                    (session_id,),
+                ).fetchone()
+            if row is None:
+                raise SessionNotFoundError("observation session was not found")
+
+            allowed_root = Path(row["allowed_root"]).expanduser().resolve()
+            session_root = Path(row["session_root"]).expanduser()
+            try:
+                unresolved_parent = session_root.parent.resolve(strict=True)
+            except OSError as exc:
+                raise SessionIntegrityError("session deletion root is unavailable") from exc
+            if (
+                unresolved_parent != allowed_root
+                or session_root.name != session_id
+                or session_root == allowed_root
+            ):
+                raise SessionIntegrityError("session deletion target escapes its allowed root")
+
+            if session_root.exists() or session_root.is_symlink():
+                try:
+                    metadata = session_root.lstat()
+                except OSError as exc:
+                    raise SessionIntegrityError("session deletion target is unavailable") from exc
+                if stat.S_ISLNK(metadata.st_mode) or not stat.S_ISDIR(metadata.st_mode):
+                    raise SessionIntegrityError("session deletion target is not a real directory")
+                tombstone = allowed_root / f".{session_id}.{uuid4().hex}.deleting"
+                try:
+                    os.replace(session_root, tombstone)
+                    shutil.rmtree(tombstone)
+                except OSError as exc:
+                    if tombstone.exists() and not session_root.exists():
+                        with _ignore_os_error():
+                            os.replace(tombstone, session_root)
+                    raise SessionIntegrityError("session evidence could not be deleted") from exc
+
+            with self._connect() as connection:
+                connection.execute("BEGIN IMMEDIATE")
+                deleted = connection.execute(
+                    "DELETE FROM observation_sessions WHERE session_id = ?",
+                    (session_id,),
+                ).rowcount
+                connection.commit()
+            if deleted != 1:
+                raise SessionNotFoundError("observation session was not found")
+
     def prepare_replay(
         self,
         session_id: str,
diff --git a/src/k1link/web/session_api.py b/src/k1link/web/session_api.py
index 59497bd..a9dedd6 100644
--- a/src/k1link/web/session_api.py
+++ b/src/k1link/web/session_api.py
@@ -303,6 +303,79 @@ def build_session_router(
                 detail="Некорректный идентификатор сессии.",
             ) from exc
 
+    @router.delete(
+        "/api/v1/observation-sessions/{session_id}",
+        status_code=204,
+    )
+    async def delete_observation_session(session_id: str) -> Response:
+        try:
+            store.get_session(session_id)
+            recorded_artifacts = store.list_recorded_media(session_id)
+        except SessionNotFoundError as exc:
+            raise HTTPException(status_code=404, detail=str(exc)) from exc
+        except ValueError as exc:
+            raise HTTPException(
+                status_code=422,
+                detail="Некорректный идентификатор сессии.",
+            ) from exc
+
+        if recording_preparation_manager is not None:
+            snapshot = recording_preparation_manager.status(session_id)
+            if snapshot is not None and snapshot.state in {
+                "queued",
+                "validating",
+                "exporting",
+                "finalizing",
+            }:
+                raise HTTPException(
+                    status_code=409,
+                    detail="Дождитесь завершения подготовки записи перед удалением.",
+                )
+            await run_in_threadpool(
+                recording_preparation_manager.release_launch_reservation,
+                session_id,
+            )
+
+        cache_deleter = getattr(recording_materializer, "delete_cached", None)
+        if callable(cache_deleter):
+            try:
+                cache_deleted = await run_in_threadpool(cache_deleter, session_id)
+            except (OSError, RecordingMaterializationError) as exc:
+                raise HTTPException(
+                    status_code=409,
+                    detail="Подготовленную запись пока нельзя удалить.",
+                ) from exc
+            if cache_deleted is not True:
+                raise HTTPException(
+                    status_code=409,
+                    detail="Запись сейчас открыта в интерфейсе. Закройте её и повторите удаление.",
+                )
+
+        if (
+            recording_preparation_manager is not None
+            and not recording_preparation_manager.discard(session_id)
+        ):
+            raise HTTPException(
+                status_code=409,
+                detail="Подготовка записи ещё выполняется.",
+            )
+
+        try:
+            await run_in_threadpool(
+                recorded_media_inspector.delete_prepared,
+                session_id,
+                (artifact.artifact_id for artifact in recorded_artifacts),
+            )
+            await run_in_threadpool(store.delete_session, session_id)
+        except SessionNotFoundError as exc:
+            raise HTTPException(status_code=404, detail=str(exc)) from exc
+        except (OSError, SessionIntegrityError) as exc:
+            raise HTTPException(
+                status_code=409,
+                detail="Сервер не смог безопасно удалить файлы этой сессии.",
+            ) from exc
+        return Response(status_code=204)
+
     @router.post("/api/v1/observation-sessions/{session_id}/replay")
     async def replay_observation_session(
         session_id: str,
diff --git a/tests/test_session_api.py b/tests/test_session_api.py
index 9a7277e..2169850 100644
--- a/tests/test_session_api.py
+++ b/tests/test_session_api.py
@@ -23,6 +23,7 @@ from k1link.sessions import (
     RecordedMediaInspector,
     ReplayCommand,
     SessionIntegrityError,
+    SessionNotFoundError,
     SessionRecordingMaterializer,
     SessionRecordingPreparationManager,
     SessionStore,
@@ -246,6 +247,116 @@ def test_session_router_lists_details_and_dispatches_opaque_replay(tmp_path: Pat
         assert_no_local_paths(value, repository)
 
 
+def test_delete_session_removes_evidence_and_cache_but_refuses_an_open_recording(
+    tmp_path: Path,
+) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    session = make_legacy_session(sessions, "20260716T205632Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+    store.reconcile_archive(xgrids_k1_archive_source(sessions))
+
+    def export_recording(source: Path, destination: Path) -> dict[str, object]:
+        payload = b"deletable-recording"
+        destination.write_bytes(payload)
+        return {
+            "source_sha256": hashlib.sha256(source.read_bytes()).hexdigest(),
+            "rrd_sha256": hashlib.sha256(payload).hexdigest(),
+            "rrd_bytes": len(payload),
+            "timeline": "session_time",
+            "timeline_start_ns": 0,
+            "timeline_end_ns": 1,
+        }
+
+    materializer = SessionRecordingMaterializer(
+        store.data_dir,
+        exporter=export_recording,
+    )
+    recording, release = materializer.materialize_pinned(store.prepare_replay(session.name))
+    router = build_session_router(store, recording_materializer=materializer)
+    delete_route = endpoint(router, "/api/v1/observation-sessions/{session_id}", "DELETE")
+
+    with pytest.raises(HTTPException) as conflict:
+        asyncio.run(delete_route(session_id=session.name))
+    assert conflict.value.status_code == 409
+    assert session.is_dir()
+    assert recording.path.is_file()
+
+    release()
+    response = asyncio.run(delete_route(session_id=session.name))
+
+    assert response.status_code == 204
+    assert not session.exists()
+    assert not recording.path.parent.exists()
+    with pytest.raises(SessionNotFoundError):
+        store.get_session(session.name)
+
+
+def test_completed_recording_get_does_not_hold_delete_for_launch_lease(
+    tmp_path: Path,
+) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    session = make_legacy_session(sessions, "20260716T205632Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+    store.reconcile_archive(xgrids_k1_archive_source(sessions))
+    payload = b"recording-opened-and-closed"
+
+    def export_recording(source: Path, destination: Path) -> dict[str, object]:
+        destination.write_bytes(payload)
+        return {
+            "source_sha256": hashlib.sha256(source.read_bytes()).hexdigest(),
+            "rrd_sha256": hashlib.sha256(payload).hexdigest(),
+            "rrd_bytes": len(payload),
+            "timeline": "session_time",
+            "timeline_start_ns": 0,
+            "timeline_end_ns": 1_000_000_000,
+        }
+
+    materializer = SessionRecordingMaterializer(store.data_dir, exporter=export_recording)
+    command = store.prepare_replay(session.name)
+    materializer.materialize(command)
+    manager = SessionRecordingPreparationManager(materializer)
+    resolved = manager.resolve_cached(command)
+    assert resolved is not None and resolved.recording is not None
+    router = build_session_router(
+        store,
+        recording_materializer=materializer,
+        recording_preparation_manager=manager,
+    )
+    replay_route = endpoint(
+        router,
+        "/api/v1/observation-sessions/{session_id}/replay",
+        "POST",
+    )
+    recording_route = endpoint(
+        router,
+        "/api/v1/observation-sessions/{session_id}/recording.rrd",
+        "GET",
+    )
+    delete_route = endpoint(router, "/api/v1/observation-sessions/{session_id}", "DELETE")
+    try:
+        replay = asyncio.run(replay_route(session_id=session.name, request=None))
+        generation = replay["launch"]["sha256"]
+        file_response = asyncio.run(
+            recording_route(
+                session_id=session.name,
+                generation=generation,
+                if_match=None,
+                if_none_match=None,
+            )
+        )
+        _, body = asyncio.run(render_file_response(file_response, range_header=None))
+        assert body == payload
+
+        deleted = asyncio.run(delete_route(session_id=session.name))
+
+        assert deleted.status_code == 204
+        assert not session.exists()
+    finally:
+        manager.close()
+
+
 def test_session_router_returns_seekable_recording_and_serves_byte_ranges(
     tmp_path: Path,
 ) -> None:
diff --git a/tests/test_session_preparation.py b/tests/test_session_preparation.py
index f96d45c..58e20f9 100644
--- a/tests/test_session_preparation.py
+++ b/tests/test_session_preparation.py
@@ -433,3 +433,38 @@ def test_launch_reservation_blocks_eviction_until_lease_expires(tmp_path: Path)
         assert not first_recording.path.exists()
     finally:
         manager.close()
+
+
+def test_first_recording_get_pin_consumes_launch_reservation(tmp_path: Path) -> None:
+    command = _command(tmp_path / "session")
+
+    def exporter(source: Path, destination: Path) -> dict[str, object]:
+        return _summary(source, destination, b"recording")
+
+    materializer = SessionRecordingMaterializer(
+        tmp_path / "private",
+        exporter=exporter,
+        free_space_reserve_bytes=0,
+    )
+    manager = SessionRecordingPreparationManager(materializer)
+    try:
+        materializer.materialize(command)
+        resolved = manager.resolve_cached(command)
+        assert resolved is not None and resolved.state == "ready"
+        reserved = manager.reserve_cached(command, lease_seconds=60.0)
+        assert reserved is not None
+
+        pinned = manager.pin_ready(
+            command.session_id,
+            preparation_id=reserved.preparation_id,
+        )
+
+        assert pinned is not None
+        _, release_response = pinned
+        assert manager.release_launch_reservation(command.session_id) is False
+        assert materializer.delete_cached(command.session_id) is False
+
+        release_response()
+        assert materializer.delete_cached(command.session_id) is True
+    finally:
+        manager.close()
diff --git a/tests/test_session_recording.py b/tests/test_session_recording.py
index f732f1a..22f706f 100644
--- a/tests/test_session_recording.py
+++ b/tests/test_session_recording.py
@@ -129,6 +129,25 @@ def test_materializer_reuses_only_a_digest_validated_private_cache(tmp_path: Pat
     assert exporter.calls == 1
 
 
+def test_delete_cached_refuses_a_live_lease_then_removes_the_exact_cache(
+    tmp_path: Path,
+) -> None:
+    command = _command(tmp_path / "source")
+    materializer = SessionRecordingMaterializer(
+        tmp_path / "private",
+        exporter=FakeExporter(),
+    )
+    recording, release = materializer.materialize_pinned(command)
+
+    assert materializer.delete_cached(command.session_id) is False
+    assert recording.path.is_file()
+
+    release()
+    assert materializer.delete_cached(command.session_id) is True
+    assert not recording.path.parent.exists()
+    assert command.primary_artifact.path.is_file()
+
+
 def test_materializer_rejects_changed_digest_bound_secondary_artifact(
     tmp_path: Path,
 ) -> None:
diff --git a/tests/test_session_store.py b/tests/test_session_store.py
index 8df74fe..e5db6e1 100644
--- a/tests/test_session_store.py
+++ b/tests/test_session_store.py
@@ -178,6 +178,39 @@ def test_catalog_reconciles_sessions_removed_from_one_evidence_root(tmp_path: Pa
     assert store.list_recent().items == ()
 
 
+def test_corrupt_candidate_does_not_starve_later_valid_session(tmp_path: Path) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    corrupt = sessions / "20260716T125502Z_viewer_live"
+    corrupt.mkdir(parents=True)
+    (corrupt / "manifest.redacted.json").write_text("{}", encoding="utf-8")
+    valid = make_legacy_session(sessions, "20260718T201659Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+
+    assert store.reconcile_archive(xgrids_k1_archive_source(sessions)) == (valid.name,)
+    assert [item.session_id for item in store.list_recent().items] == [valid.name]
+
+
+def test_present_corrupt_candidate_does_not_delete_its_last_valid_catalog_row(
+    tmp_path: Path,
+) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    retained = make_legacy_session(sessions, "20260716T125502Z_viewer_live")
+    later = make_legacy_session(sessions, "20260718T201659Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+    source = xgrids_k1_archive_source(sessions)
+    assert store.reconcile_archive(source) == (retained.name, later.name)
+
+    shutil.rmtree(retained / "captures")
+
+    assert store.reconcile_archive(source) == (later.name,)
+    assert {item.session_id for item in store.list_recent().items} == {
+        retained.name,
+        later.name,
+    }
+
+
 def test_catalog_uses_valid_project_name_as_session_display_name(tmp_path: Path) -> None:
     sessions = tmp_path / "sessions"
     session = make_legacy_session(sessions, "20260716T205632Z_viewer_live")
@@ -671,6 +704,45 @@ def test_current_session_marker_keeps_active_capture_out_of_replay(tmp_path: Pat
     assert store.get_session(session.name).summary.replayable is True
 
 
+def test_delete_session_removes_only_the_exact_evidence_tree_and_catalog_row(
+    tmp_path: Path,
+) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    deleted = make_legacy_session(sessions, "20260716T205632Z_viewer_live")
+    retained = make_legacy_session(sessions, "20260716T205633Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+    store.reconcile_archive(xgrids_k1_archive_source(sessions))
+
+    store.delete_session(deleted.name)
+
+    assert not deleted.exists()
+    assert retained.is_dir()
+    with pytest.raises(SessionNotFoundError):
+        store.get_session(deleted.name)
+    assert store.get_session(retained.name).summary.session_id == retained.name
+
+
+def test_delete_session_rejects_a_catalog_target_outside_its_allowed_root(
+    tmp_path: Path,
+) -> None:
+    repository = tmp_path / "repo"
+    sessions = repository / "sessions"
+    session = make_legacy_session(sessions, "20260716T205632Z_viewer_live")
+    store = SessionStore(repository, data_dir=tmp_path / "data")
+    store.reconcile_archive(xgrids_k1_archive_source(sessions))
+    with sqlite3.connect(store.database_path) as connection:
+        connection.execute(
+            "UPDATE observation_sessions SET session_root = ? WHERE session_id = ?",
+            (str(repository), session.name),
+        )
+
+    with pytest.raises(SessionIntegrityError, match="escapes"):
+        store.delete_session(session.name)
+
+    assert session.is_dir()
+
+
 def test_interrupted_capture_replays_only_committed_prefix_before_partial_raw_tail(
     tmp_path: Path,
 ) -> None: