fix(merge): integrate gitea/main fork — renumber migrations, dedup, fix paired_tasks insert

Resolves the gitea/main <-> deployed-line merge:
- DB migrations: renumber gitea's colliding 019/020 to 021/022
  (reviewer_failure_count -> v21, turn_progress_text_compat -> v22) so all
  four migrations have distinct versions; update ordered list + bootstrap test.
- paired_tasks INSERT: add the missing VALUES placeholder so both new columns
  (reviewer_failure_count + arbiter_intervention_count) bind (26 cols/values).
- index.ts: drop duplicate startUsagePrimer import from the auto-merge.
- discord output: keep the deployed pipeline (attachment rejection notice) and
  call sanitizeForOutbound at the channel boundary so prose escaping done in
  prepareDiscordOutbound is not double-applied; keep gitea's reviewer
  silent-failure cap + router markdown-escape helpers.
- usage-primer/codex-warmup: keep the dawn-hold removal over gitea's primer.

Full test suite: only pre-existing env/bun-path failures remain; no merge regressions.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/index.ts

@@ -55,7 +55,6 @@ import { nudgeSchedulerLoop, startSchedulerLoop } from './task-scheduler.js';
 import { startUnifiedDashboard } from './unified-dashboard.js';
 import { startUsagePrimer } from './usage-primer.js';
 import { startWebDashboardServer } from './web-dashboard-server.js';
-import { startUsagePrimer } from './usage-primer.js';
 import { Channel, NewMessage, RegisteredGroup } from './types.js';
 import { logger } from './logger.js';
 import { initCodexTokenRotation } from './codex-token-rotation.js';