feat(FN-980): add mission autopilot for autonomous slice progression

- Add MissionAutopilot class with state machine (inactive → watching → activating → completing)
- Add autopilot database schema: autopilotEnabled, autopilotState, lastAutopilotActivityAt columns
- Integrate autopilot with scheduler: handleTaskCompletion() triggers slice activation
- Add API routes: GET/PATCH /missions/:id/autopilot, POST start/stop endpoints
- Add autopilot toggle UI in MissionManager dashboard component
- Add retry logic with exponential backoff (up to 3 attempts) for slice activation
- Add background poll (60s) to detect stale autopilot missions
- Include changeset for @gsxdsm/fusion minor bump

packages/engine/src/logger.ts

@@ -76,3 +76,6 @@ export const projectManagerLog = createLogger("project-manager");
 
 /** Logger for the hybrid executor subsystem. */
 export const hybridExecutorLog = createLogger("hybrid-executor");
+
+/** Logger for the mission autopilot subsystem. */
+export const autopilotLog = createLogger("autopilot");