feat(dashboard-agent-db): run migrations over a direct (non-pooler) connection (#4054)

## Summary

The in-dashboard agent's datastore now runs migrations over a direct
(non-pooler) connection. A transaction-mode pooler can't run the
migrator (no advisory locks, no multi-statement DDL), so when the
agent's database sits behind a pooler the migration step needs a
separate direct connection.

The application keeps connecting over the pooled
`DASHBOARD_AGENT_DATABASE_URL`. Only the migration entry points changed
(`drizzle.config.ts`, `migrate.mjs`, `migrate-status.mjs`); the runtime
client is untouched.

## Connection resolution (migrations)

```
DASHBOARD_AGENT_DIRECT_URL    direct agent connection (used for migrations)
DASHBOARD_AGENT_DATABASE_URL  pooled agent connection (preserves current behavior)
DIRECT_URL                    main direct connection (single-database fallback)
DATABASE_URL                  last resort
```

Mirrors the existing `DATABASE_URL` / `DIRECT_URL` split. Fully
backward-compatible: with nothing new set, resolution is identical to
before. The agent-specific vars take precedence over the main
`DIRECT_URL`, so a separate agent database is never migrated against the
wrong one. When the agent falls back to the main single database,
migrations now prefer its direct connection.

internal-packages/dashboard-agent-db/README.md

@@ -4,10 +4,13 @@ The conversation datastore for the in-dashboard agent, isolated from the main
 Prisma database. Drizzle (postgres-js) over a dedicated `trigger_dashboard_agent`
 Postgres schema.
 
-- **Cloud:** a separate PlanetScale Postgres database (`DASHBOARD_AGENT_DATABASE_URL`),
-  reached over a standard pooled connection.
-- **OSS / self-host:** falls back to the main `DATABASE_URL`; the tables live in
-  the dedicated `trigger_dashboard_agent` schema, isolated from Prisma's `public`.
+- **Cloud:** a separate PlanetScale Postgres database. The app connects over a
+  pooled connection (`DASHBOARD_AGENT_DATABASE_URL`); migrations run over a direct
+  (non-pooler) connection (`DASHBOARD_AGENT_DIRECT_URL`), since a transaction-mode
+  pooler can't run the migrator.
+- **OSS / self-host:** falls back to the main `DATABASE_URL` (and `DIRECT_URL` for
+  migrations); the tables live in the dedicated `trigger_dashboard_agent` schema,
+  isolated from Prisma's `public`.
 
 The schema is **foreign-key-free** — it references main entities (`organizationId`,
 `userId`) by id only, because in cloud it lives in a different database.
@@ -36,7 +39,7 @@ of truth.
 
 ```bash
 pnpm run db:generate   # generate SQL migration from src/schema.ts (offline)
-pnpm run db:migrate    # apply migrations (needs DASHBOARD_AGENT_DATABASE_URL or DATABASE_URL)
+pnpm run db:migrate    # apply migrations (direct url: DASHBOARD_AGENT_DIRECT_URL, falling back to DASHBOARD_AGENT_DATABASE_URL / DIRECT_URL / DATABASE_URL)
 ```
 
 drizzle-kit is scoped to the `trigger_dashboard_agent` schema (`schemaFilter`), so

internal-packages/dashboard-agent-db/drizzle.config.ts

@@ -1,9 +1,13 @@
 import { defineConfig } from "drizzle-kit";
 
-// Cloud points at the dedicated PlanetScale database; OSS falls back to the main
-// DATABASE_URL (tables still land in the trigger_dashboard_agent schema).
+// Migrations need a direct (non-pooler) connection; a transaction-mode pooler
+// can't run the migrator. Prefer the agent's direct url, then its pooled url,
+// then the main DIRECT_URL/DATABASE_URL (OSS single-database fallback; tables
+// still land in the trigger_dashboard_agent schema).
 const url =
+  process.env.DASHBOARD_AGENT_DIRECT_URL ??
   process.env.DASHBOARD_AGENT_DATABASE_URL ??
+  process.env.DIRECT_URL ??
   process.env.DATABASE_URL ??
   "postgres://placeholder"; // generate is offline; a real url is only needed for migrate/studio
 

internal-packages/dashboard-agent-db/migrate-status.mjs

@@ -8,11 +8,16 @@ import postgres from "postgres";
 const MIGRATIONS_SCHEMA = "drizzle";
 const MIGRATIONS_TABLE = "__dashboard_agent_migrations";
 
-const connectionString = process.env.DASHBOARD_AGENT_DATABASE_URL ?? process.env.DATABASE_URL;
+// Match migrate.mjs: a direct (non-pooler) connection, same precedence.
+const connectionString =
+  process.env.DASHBOARD_AGENT_DIRECT_URL ??
+  process.env.DASHBOARD_AGENT_DATABASE_URL ??
+  process.env.DIRECT_URL ??
+  process.env.DATABASE_URL;
 
 if (!connectionString) {
   console.error(
-    "[dashboard-agent-db] DASHBOARD_AGENT_DATABASE_URL / DATABASE_URL not set; cannot check status."
+    "[dashboard-agent-db] No database url set (DASHBOARD_AGENT_DIRECT_URL / DASHBOARD_AGENT_DATABASE_URL / DIRECT_URL / DATABASE_URL); cannot check status."
   );
   process.exit(2);
 }

internal-packages/dashboard-agent-db/migrate.mjs

@@ -10,13 +10,19 @@ import { drizzle } from "drizzle-orm/postgres-js";
 import { migrate } from "drizzle-orm/postgres-js/migrator";
 import postgres from "postgres";
 
-// Cloud points at the dedicated dashboard-agent database; OSS falls back to the
-// main DATABASE_URL (tables still land in the `trigger_dashboard_agent` schema).
-const connectionString = process.env.DASHBOARD_AGENT_DATABASE_URL ?? process.env.DATABASE_URL;
+// Migrations need a direct (non-pooler) connection; a transaction-mode pooler
+// can't run the migrator. Prefer the agent's direct url, then its pooled url,
+// then the main DIRECT_URL/DATABASE_URL (OSS single-database fallback; tables
+// still land in the `trigger_dashboard_agent` schema).
+const connectionString =
+  process.env.DASHBOARD_AGENT_DIRECT_URL ??
+  process.env.DASHBOARD_AGENT_DATABASE_URL ??
+  process.env.DIRECT_URL ??
+  process.env.DATABASE_URL;
 
 if (!connectionString) {
   console.error(
-    "[dashboard-agent-db] DASHBOARD_AGENT_DATABASE_URL / DATABASE_URL not set; cannot migrate."
+    "[dashboard-agent-db] No database url set (DASHBOARD_AGENT_DIRECT_URL / DASHBOARD_AGENT_DATABASE_URL / DIRECT_URL / DATABASE_URL); cannot migrate."
   );
   process.exit(1);
 }