fix(ai): sync provider configuration and keys across linked devices (#1506)

src/backend/tests/fixtures/upgrade/upgrade-postgres.sql

@@ -929,6 +929,9 @@ CREATE INDEX IF NOT EXISTS "idx_ai_proposals_user" ON "ai_proposals" ("user_id",
 CREATE INDEX IF NOT EXISTS "idx_ai_proposals_conversation" ON "ai_proposals" ("conversation_id");
 ALTER TABLE "ai_proposals" RENAME TO "p_ai_proposals";
 
+-- ==== plugin ai 0002_provider_sync.sql ====
+ALTER TABLE "p_ai_providers" ADD COLUMN "sync_id" varchar(255) UNIQUE;
+
 -- ==== plugin alerts 0001_create_alerts.sql ====
 -- alerts 0001: create_alerts
 -- Generated by termix-plugin migrations. Review before committing.