T2/Phase 2A: port auth + infrastructure routes to Hono (~8 routes)

- /api/health: DB ping + version + uptime
   - /api/auth/*: NextAuth -> Auth.js standalone (credentials + passkey)
   - /api/domains: full CRUD
   - /api/realtime: SSE with PostgreSQL LISTEN/NOTIFY
   - /mcp: JSON-RPC 2.0 (initialize, tools/list, tools/call, resources/*)

   Parent: t_e1cbd87d -> t_d8654a91 (T1)

apps/api/src/routes/health.ts

@@ -0,0 +1,27 @@
+import { db, sql } from "@project-e/db";
+
+export async function healthHandler() {
+  const start = Date.now();
+  let dbOk = false;
+  let dbPingMs = 0;
+  try {
+    const result = await sql`SELECT 1 AS ok`;
+    dbOk = true;
+    dbPingMs = Date.now() - start;
+  } catch {
+    dbOk = false;
+    dbPingMs = -1;
+  }
+
+  return {
+    status: dbOk ? "ok" : "degraded",
+    timestamp: new Date().toISOString(),
+    version: process.env.npm_package_version || "0.1.0",
+    runtime: "bun",
+    uptime: process.uptime(),
+    database: {
+      connected: dbOk,
+      ping_ms: dbPingMs,
+    },
+  };
+}