[medium] Chat screen, feed and store state bugs (grouped) #491

Severity: medium

• Body: remote search overwrites pinned/archived flags; delete invalidates the wrong query key; auto-title PATCH omits the profile; onRehydrateStorage references the store before assignment (hydration never completes); unguarded storage in actions; flags migration, event scoping and per-session stores ignore the profile. (The stale session-list cache write and the identical-reply dedupe are already tracked.)
• Evidence: sessions-feed.ts:1276-1283,1458; use-delete-session.ts:92,98; use-auto-session-title.ts:161-168; terminal-panel-store.ts:187,201; session-flags-migration.ts:50,133-141.

Already tracked: #378, #441

Source: docs/overnight-2026-10-26/round2/issues-draft-2.md § HS18
Filed from the 2026-10-26 overnight audit (read-only findings, not yet triaged).