feat(KB-635): add Mission system integration across CLI, engine, and dashboard

- Add mission CLI commands: create, list, show, delete, activate-slice
- Add pi extension tools for mission management
- Add MissionStore helper methods and Mission types
- Add scheduler mission awareness for automatic slice activation
- Add engine integration wiring for mission-aware task execution
- Add dashboard mission routes and API endpoints
- Link tasks to missions via sliceId field with autoAdvance support

packages/engine/src/executor.ts

@@ -1830,7 +1830,7 @@ git log --oneline
       "",
       "## Steering Comments",
       "",
-      "The following steering comments were added by the user during execution. Consider adjusting your approach or replanning remaining steps based on this feedback.",
+      "The following comments were added by the user during execution. Consider adjusting your approach or replanning remaining steps based on this feedback.",
       "",
     ];
     for (const comment of recentComments) {