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.

src/observability/logger.ts

@@ -0,0 +1,42 @@
+import pino from 'pino';
+import type { Logger } from 'pino';
+
+export type { Logger };
+
+/**
+ * Builds the root pino logger. Called once at startup with the config values.
+ *
+ * In development, pino-pretty is used for human-readable output (lazy import
+ * so it is never bundled in production paths). In test/production, raw JSON is
+ * emitted — fast and parseable by log aggregators.
+ */
+export function createLogger(options: {
+  level: string;
+  nodeEnv: string;
+  instanceId: string;
+}): Logger {
+  const { level, nodeEnv, instanceId } = options;
+
+  const base = {
+    service: 'tcp-ingestion',
+    instance_id: instanceId,
+  };
+
+  if (nodeEnv === 'development') {
+    return pino({
+      level,
+      base,
+      transport: {
+        target: 'pino-pretty',
+        options: {
+          colorize: true,
+          translateTime: 'SYS:standard',
+          ignore: 'pid,hostname',
+        },
+      },
+    });
+  }
+
+  // Production and test: plain JSON — fast, no extra deps
+  return pino({ level, base });
+}