feat(fleet): add board observation center with live sources and maps

Add adaptive per-vehicle layouts, full-panel dragging, source controls and automatic preview recovery for RealSense, Insta360 X4 and XGRIDS K1 observation views. Integrate cached Cesium map layers through the private NAS gateway link, retain bounded sensor command receipts, and document validation and operational handoff.

src/k1link/fleet/sensors.py

@@ -33,6 +33,8 @@ ACTIONS = {
 }
 MAX_INVENTORY_ITEMS = 500
 MAX_SENSOR_STATE_BYTES = 3 * 1024 * 1024
+MAX_PENDING_COMMANDS = 32
+MAX_COMMAND_RECEIPTS = 128
 
 
 def validate_inventory(value, node_id):
@@ -94,8 +96,29 @@ def submit(fleet, vehicle_id, value):
         row["sensor_commands"] = {
             k: v for k, v in row["sensor_commands"].items() if time.time() - v["updated_at"] < 600
         }
-        if len(row["sensor_commands"]) >= 32:
+        now = datetime.now(UTC)
+        # Completed viewing operations are receipts, not occupied execution
+        # slots. Keep them for idempotency without blocking a later Stop.
+        active = sum(
+            entry["state"] in ("queued", "running")
+            and datetime.fromisoformat(entry["command"]["deadline_at"]) > now
+            for entry in row["sensor_commands"].values()
+        )
+        if active >= MAX_PENDING_COMMANDS:
             raise PairingError("Слишком много запросов к устройству. Повторите позже.")
+        if len(row["sensor_commands"]) >= MAX_COMMAND_RECEIPTS:
+            expired = sorted(
+                (k for k, entry in row["sensor_commands"].items()
+                 if entry["state"] not in ("queued", "running")
+                 and datetime.fromisoformat(entry["command"]["deadline_at"]) < now),
+                key=lambda k: row["sensor_commands"][k]["updated_at"],
+            )
+            for key in expired:
+                del row["sensor_commands"][key]
+                if len(row["sensor_commands"]) < MAX_COMMAND_RECEIPTS:
+                    break
+            if len(row["sensor_commands"]) >= MAX_COMMAND_RECEIPTS:
+                raise PairingError("Слишком много запросов к устройству. Повторите позже.")
         operation = {"command": value, "state": "queued", "updated_at": time.time()}
         row["sensor_commands"][command.operation_id] = operation
         fleet.save(row)