fix(replay): recover failed archives and release deleted sessions

apps/control-station/test/observationSessions.test.mjs

@@ -17,6 +17,7 @@ let ObservationSessionApiError;
 let ObservationSessionContractError;
 let decodeObservationRecordedMediaManifest;
 let createObservationReplayCoordinator;
+let deleteObservationSessionAfterTeardown;
 let resolveObservationSessionReplay;
 let waitForObservationReplayPreparation;
 let storeObservationReplayPreparation;
@@ -45,6 +46,7 @@ before(async () => {
   } = await server.ssrLoadModule("/src/core/observation/sessionArchive.ts"));
   ({
     createObservationReplayCoordinator,
+    deleteObservationSessionAfterTeardown,
     resolveObservationSessionReplay,
     waitForObservationReplayPreparation,
     storeObservationReplayPreparation,
@@ -437,6 +439,56 @@ test("delete API uses one opaque same-origin target and requires an empty 204",
   );
 });
 
+test("session deletion releases the selected presentation before the DELETE request", async () => {
+  const events = [];
+  await deleteObservationSessionAfterTeardown("session-20260716T205632Z", {
+    onDeleteBegin: async (sessionId) => {
+      events.push(`release:${sessionId}`);
+    },
+    deleteSession: async (sessionId) => {
+      events.push(`delete:${sessionId}`);
+    },
+  });
+  assert.deepEqual(events, [
+    "release:session-20260716T205632Z",
+    "delete:session-20260716T205632Z",
+  ]);
+
+  let deleteCalled = false;
+  await assert.rejects(
+    deleteObservationSessionAfterTeardown("session-20260716T205632Z", {
+      onDeleteBegin: async () => {
+        throw new Error("viewer teardown failed");
+      },
+      deleteSession: async () => {
+        deleteCalled = true;
+      },
+    }),
+    /viewer teardown failed/,
+  );
+  assert.equal(deleteCalled, false);
+});
+
+test("App atomically clears the selected Rerun source before deleting its session", async () => {
+  const appSource = await readFile(new URL("../src/App.tsx", import.meta.url), "utf8");
+  assert.match(
+    appSource,
+    /selectedRecordedSessionIdRef\.current = session\.id[\s\S]*setRecordedReplay\(launch\)/,
+  );
+  assert.match(
+    appSource,
+    /releaseRecordedReplayForDelete[\s\S]*selectedRecordedSessionIdRef\.current !== sessionId[\s\S]*selectedRecordedSessionIdRef\.current = null[\s\S]*setRecordedReplay\(null\)[\s\S]*setSourceUrl\(""\)/,
+  );
+  assert.match(
+    appSource,
+    /onDeleteBegin=\{releaseRecordedReplayForDelete\}/,
+  );
+  assert.match(
+    appSource,
+    /onDeleteBegin:\s*releaseRecordedReplayForDelete/,
+  );
+});
+
 test("replay API accepts only a same-origin seekable recording descriptor", async () => {
   const calls = [];
   const launch = await replayObservationSession("session-20260716T205632Z", {