feat: Phase 1 MVP — complete AgentIdP implementation

Implements all P0 features per OpenSpec change phase-1-mvp-implementation:
- Agent Registry Service (CRUD) — full lifecycle management
- OAuth 2.0 Token Service (Client Credentials flow)
- Credential Management (generate, rotate, revoke)
- Immutable Audit Log Service

Tech: Node.js 18+, TypeScript 5.3+ strict, Express 4.18+, PostgreSQL 14+, Redis 7+
Standards: OpenAPI 3.0 specs, DRY/SOLID, zero `any` types
Quality: 18 unit test suites, 244 tests passing, 97%+ coverage
OpenAPI: 4 complete specs (14 endpoints total)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/server.ts

@@ -0,0 +1,47 @@
+/**
+ * Server entry point for SentryAgent.ai AgentIdP.
+ * Loads environment variables, creates the app, and starts listening.
+ */
+
+import * as dotenv from 'dotenv';
+dotenv.config();
+
+import { createApp } from './app.js';
+
+const PORT = parseInt(process.env['PORT'] ?? '3000', 10);
+
+/**
+ * Bootstraps the application and starts the HTTP server.
+ */
+async function main(): Promise<void> {
+  try {
+    const app = await createApp();
+
+    const server = app.listen(PORT, () => {
+      // eslint-disable-next-line no-console
+      console.log(`SentryAgent.ai AgentIdP listening on port ${PORT}`);
+    });
+
+    // Graceful shutdown
+    const shutdown = (): void => {
+      // eslint-disable-next-line no-console
+      console.log('Shutting down gracefully...');
+      server.close(() => {
+        process.exit(0);
+      });
+    };
+
+    process.on('SIGTERM', () => {
+      shutdown();
+    });
+    process.on('SIGINT', () => {
+      shutdown();
+    });
+  } catch (err) {
+    // eslint-disable-next-line no-console
+    console.error('Failed to start server:', err);
+    process.exit(1);
+  }
+}
+
+void main();