Implement Phase 1 task 1.8 (Redis Streams publisher + main wiring)

- Bounded in-memory queue (default 10000); overflow throws PublishOverflowError
  so the framing layer skips ACK and the device retransmits.
- Background worker drains via XADD with MAXLEN ~ approximate trimming.
- JSON serialization with sentinel encoding for bigint/Buffer/Date; correctly
  handles Buffer.prototype.toJSON firing before the replacer.
- AdapterContext.publish(position, codec) with codec-label closure at dispatch
  in adapters/teltonika/index.ts; zero changes to the three codec parsers.
- connectRedis with retry-on-startup; main.ts wires the full pipeline.
- installGracefulShutdown stubbed (full hardening in task 1.12).
- 19 new tests (17 unit + 2 Docker-conditional integration). Total 81 passing.

src/config/load.ts

@@ -19,6 +19,9 @@ const ConfigSchema = z.object({
   // Observability
   METRICS_PORT: z.coerce.number().int().min(0).max(65535).default(9090),
 
+  // Publisher queue — capacity of the bounded in-memory queue before overflow
+  PUBLISH_QUEUE_CAPACITY: z.coerce.number().int().min(1).default(10_000),
+
   // Device authority — off by default; opt-in for strict reject-on-unknown
   STRICT_DEVICE_AUTH: z
     .string()