feat(KB-636): launch missions feature

- Add MissionStore integration tests for core mission operations

- Add mission API end-to-end tests for dashboard endpoints

- Add Missions documentation to README with usage examples

- Update CLI help text with mission commands

- Add changeset for missions package release

packages/cli/src/bin.ts

@@ -98,6 +98,8 @@ Usage:
   fn mission create [title] [description]  Create a new mission
   fn mission list                       List all missions
   fn mission show <id>                  Show mission with hierarchy
+  fn mission delete <id> [--force]      Delete mission
+  fn mission activate-slice <slice-id>  Activate a pending slice
   fn mission delete <id> [--force]      Delete a mission
   fn mission activate-slice <slice-id>  Activate a pending slice