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/db/bootstrap.test.ts

@@ -164,15 +164,15 @@ describe('initializeDatabaseSchema', () => {
       expect(columns).toContain('progress_updated_at');
 
       // The pre-existing version-15 row is left untouched; the compat migration
-      // (version 20) is what reconciles the schema.
+      // (version 22 after merge-renumbering) is what reconciles the schema.
       const version15 = database
         .prepare('SELECT name FROM schema_migrations WHERE version = 15')
         .get() as { name: string };
       expect(version15.name).toBe('reviewer_failure_count');
-      const version20 = database
-        .prepare('SELECT name FROM schema_migrations WHERE version = 20')
+      const version22 = database
+        .prepare('SELECT name FROM schema_migrations WHERE version = 22')
         .get() as { name: string } | null;
-      expect(version20?.name).toBe('turn_progress_text_compat');
+      expect(version22?.name).toBe('turn_progress_text_compat');
     } finally {
       database.close();
     }

src/db/paired-state.ts

@@ -191,7 +191,7 @@ export function createPairedTaskInDatabase(
           created_at,
           updated_at
         )
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
       `,
     )
     .run(