chore(search): retimestamp ru_en migration to 20260707T130000 to avoid collision (#529)

Develop introduced two migrations at the exact 20260707T120000 stamp
(ai-chat-metadata, page-history-kind). Three files sharing one timestamp
is fragile for deploy ordering, so move #529's ru_en-config migration to a
strictly-later, unique 20260707T130000 so it orders cleanly last. It touches
only the ru_en text-search config (different tables), so running it after the
develop migrations is order-independent and safe.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/core/search/search.service.ts

@@ -24,7 +24,7 @@ import {
 const tsquery = require('pg-tsquery')();
 
 // The FTS text-search configuration used on BOTH the stored side (pages.tsv via
-// its trigger, see migration 20260707T120000) and the query side here. #529
+// its trigger, see migration 20260707T130000) and the query side here. #529
 // acceptance #13 invariant: column config and query config always change as a
 // pair — flip this only alongside the migration.
 const TS_CONFIG = 'ru_en';