Implement Phase 1 tasks 1.1-1.4 (scaffold + core shell + Teltonika framing)

- Project scaffold (Node 22 + TS 5 + pnpm + vitest + ESLint flat config)
- Core shell: TCP server, session loop, adapter registry, types
- Configuration (zod-validated env) and pino logger
- Teltonika adapter: IMEI handshake, frame envelope, CRC-16/IBM,
  codec dispatch registry, DeviceAuthority seam (AllowAllAuthority default)

Codec data parsers (1.5-1.7), Redis publisher (1.8), and downstream
tasks remain. 36 tests covering CRC, framing, handshake, device
authority, config, and core server. typecheck/lint/test/build all clean.

test/core/server.test.ts

@@ -0,0 +1,74 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import * as net from 'node:net';
+import type { Logger } from 'pino';
+import type { Adapter, AdapterContext, Metrics, Position } from '../../src/core/types.js';
+import { startServer } from '../../src/core/server.js';
+
+function makeMockContext(): AdapterContext {
+  const logger = {
+    debug: vi.fn(),
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+    child: vi.fn().mockReturnThis(),
+  } as unknown as Logger;
+
+  const metrics: Metrics = {
+    inc: vi.fn(),
+    observe: vi.fn(),
+  };
+
+  return {
+    publish: vi.fn(async (_p: Position) => {}),
+    logger,
+    metrics,
+  };
+}
+
+describe('startServer', () => {
+  const servers: net.Server[] = [];
+
+  afterEach(() => {
+    for (const server of servers) {
+      server.close();
+    }
+    servers.length = 0;
+  });
+
+  it('invokes handleSession with a real socket when a client connects', async () => {
+    const handleSession = vi.fn().mockResolvedValue(undefined);
+
+    const adapter: Adapter = {
+      name: 'test-adapter',
+      ports: [0], // port 0 = OS-assigned ephemeral port
+      handleSession,
+    };
+
+    const ctx = makeMockContext();
+    const server = startServer(0, adapter, ctx);
+    servers.push(server);
+
+    // Wait for the server to start listening
+    const port = await new Promise<number>((resolve) => {
+      server.on('listening', () => {
+        const addr = server.address();
+        resolve(typeof addr === 'object' && addr !== null ? addr.port : 0);
+      });
+    });
+
+    // Connect a client
+    const client = new net.Socket();
+    client.connect(port, '127.0.0.1');
+
+    // Wait for handleSession to be called
+    await vi.waitFor(() => expect(handleSession).toHaveBeenCalledOnce(), { timeout: 2000 });
+
+    const [socketArg, ctxArg] = handleSession.mock.calls[0] as [net.Socket, AdapterContext];
+    expect(socketArg).toBeInstanceOf(net.Socket);
+    expect(ctxArg).toBeDefined();
+    expect(typeof ctxArg.publish).toBe('function');
+    expect(ctxArg.logger).toBeDefined();
+
+    client.destroy();
+  });
+});