Q132: remove PR bot gates that no task completion or goal close consulted

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main/database/migrations/095-drop-pr-bot-gates.ts

@@ -0,0 +1,7 @@
+// PR bot gates were switches that no task completion or goal close ever consulted, so turning one on blocked nothing.
+export const dropPrBotGatesSchema = `
+  drop table if exists pr_bot_gates;
+
+  insert into schema_migrations(version, name, applied_at)
+  values (95, 'drop_pr_bot_gates', datetime('now'));
+`;