fix: NATS pipeline bugs, add integration tests and service runners

Fix three critical bugs preventing the NATS message pipeline from working:

- FlowProcessor now subscribes to config-push topic (was missing entirely),
  using DeliverPolicy.All to replay config on service restart
- NATS streams use wildcard subjects (tg.flow.>) instead of per-topic
  narrow filters that caused 503 errors on publish
- Subscriber dispatch loop has exponential backoff on errors to prevent
  tight error loops

Add service runner scripts (gateway, config, LLM) and a 7-test
integration suite that verifies config CRUD, WebSocket round-trip,
and full LLM text-completion through the NATS pipeline.

Fix Docker Compose infra: pin Tempo to v2.6.1, remove deprecated Loki
config fields, add user:0 for volume permissions, remap conflicting
ports (FalkorDB 6380, OTLP 4327/4328).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ts/scripts/run-config.ts

@@ -0,0 +1,15 @@
+/**
+ * Start the config service.
+ *
+ * Usage: pnpm tsx scripts/run-config.ts
+ *
+ * Env:
+ *   NATS_URL           (default: nats://localhost:4222)
+ *   CONFIG_PERSIST_PATH (optional, e.g., ./data/config.json)
+ */
+import { run } from "../packages/flow/src/config/service.js";
+
+run().catch((err) => {
+  console.error("Config service failed:", err);
+  process.exit(1);
+});