feat(TRUEREF-0020): add job status page with pause/resume/cancel controls

- Extend indexing_jobs schema to support 'paused' and 'cancelled' status
- Add JobQueue methods: pauseJob(), resumeJob(), cancelJob()
- Create POST /api/v1/jobs/[id]/{pause,resume,cancel} endpoints
- Implement /admin/jobs page with auto-refresh (3s polling)
- Add JobStatusBadge component with color-coded status display
- Action buttons appear contextually based on job status
- Optimistic UI updates with error handling
- All 477 existing tests pass, no regressions

src/lib/server/db/schema.ts

@@ -132,7 +132,7 @@ export const indexingJobs = sqliteTable('indexing_jobs', {
 		.references(() => repositories.id, { onDelete: 'cascade' }),
 	versionId: text('version_id'),
 	status: text('status', {
-		enum: ['queued', 'running', 'done', 'failed']
+		enum: ['queued', 'running', 'paused', 'cancelled', 'done', 'failed']
 	})
 		.notNull()
 		.default('queued'),