feat(obs, net): Add Tempo service and enable dual-stack listener (#192)

This commit introduces two key enhancements: the integration of Grafana Tempo for distributed tracing and the implementation of a dual-stack TCP listener for improved network compatibility.

- **Observability**:
  - Adds the `tempo` service to the `docker-compose.yml` observability stack.
  - Tempo is configured to collect and store traces, integrating with the existing OpenTelemetry setup.
  - A custom `tempo-entrypoint.sh` script is included to manage volume permissions on startup.

- **Networking**:
  - Modifies `http.rs` to support dual-stack (IPv4/IPv6) connections on a single socket.
  - By setting the `IPV6_V6ONLY` socket option to `false`, the server can now accept both IPv6 and IPv4-mapped IPv6 traffic, enhancing cross-platform support.

.docker/observability/prometheus.yml

@@ -18,8 +18,11 @@ global:
 scrape_configs:
   - job_name: 'otel-collector'
     static_configs:
-      - targets: ['otel-collector:8888']  # 从 Collector 刮取指标
+      - targets: [ 'otel-collector:8888' ]  # 从 Collector 刮取指标
   - job_name: 'otel-metrics'
     static_configs:
-      - targets: ['otel-collector:8889']  # 应用指标
+      - targets: [ 'otel-collector:8889' ]  # 应用指标
+  - job_name: 'tempo'
+    static_configs:
+      - targets: [ 'tempo:3200' ]