feat(server): vendor createPool in-repo, drop dead @lilith/quinn-db-pg

The @lilith/quinn-db-pg@1.0.1-dev.* snapshot was only ever published to the
retired black.lan Verdaccio and resolves nowhere now (not on the DO forge, no
local cache, no source). Replace the single `createPool` import with a faithful
in-repo pg.Pool factory (service-name -> QUINN_<SERVICE>_DB_URL) and add `pg`
as a direct dependency (was transitive via the dead package).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/server/package.json

@@ -10,8 +10,8 @@
     "test": "bun test"
   },
   "dependencies": {
-    "@lilith/quinn-db-pg": "1.0.1-dev.1776900251",
     "hono": "^4.6.0",
+    "pg": "^8.13.0",
     "zod": "^3.23.0"
   },
   "devDependencies": {

src/server/src/shared/db/index.ts

@@ -1,5 +1,5 @@
 import { Pool, type QueryResultRow } from 'pg';
-import { createPool } from '@lilith/quinn-db-pg';
+import { createPool } from './pool';
 
 export type Sql = Pool;
 

src/server/src/shared/db/pool.ts

@@ -0,0 +1,38 @@
+import { Pool } from 'pg';
+import { logger } from '@/shared/logger';
+
+/**
+ * Service-keyed Postgres pool factory.
+ *
+ * Each service reads its own connection string from `QUINN_<SERVICE>_DB_URL`
+ * (e.g. service `macsync` → `QUINN_MACSYNC_DB_URL`). The URL points at the local
+ * pgBouncer (`127.0.0.1:6432`), which terminates TLS to the DO Managed PG
+ * upstream — so the app→bouncer hop is plaintext on the loopback and needs no
+ * `ssl` block here.
+ *
+ * Vendored in-repo (was `@lilith/quinn-db-pg`) — that registry lived on the
+ * retired `black` host and is gone; this is the faithful, self-contained pool.
+ */
+export function createPool(serviceName: string): Pool {
+  const envKey = `QUINN_${serviceName.toUpperCase().replace(/-/g, '_')}_DB_URL`;
+  const connectionString = process.env[envKey];
+  if (!connectionString) {
+    throw new Error(`${envKey} is required (no default — set the connection string in env)`);
+  }
+
+  const pool = new Pool({
+    connectionString,
+    max: Number(process.env['DB_POOL_MAX'] ?? 10),
+    idleTimeoutMillis: 30_000,
+    connectionTimeoutMillis: 10_000,
+  });
+
+  // An idle backend dropping the connection emits 'error' on the pool; without a
+  // handler node-postgres rethrows and crashes the process. Log and let the pool
+  // evict/replace the client on next checkout.
+  pool.on('error', (err) => {
+    logger.error(`db: idle client error`, { service: serviceName, err: err.message });
+  });
+
+  return pool;
+}