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.

Cargo.lock

@@ -3540,6 +3540,18 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a3d8a32ae18130a3c84dd492d4215c3d913c3b07c6b63c2eb3eb7ff1101ab7bf"
 
+[[package]]
+name = "enum-as-inner"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1e6a265c649f3f5979b601d26f1d05ada116434c87741c9493cb56218f76cbc"
+dependencies = [
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.104",
+]
+
 [[package]]
 name = "enumflags2"
 version = "0.7.12"
@@ -7899,6 +7911,7 @@ dependencies = [
  "serde_urlencoded",
  "shadow-rs",
  "socket2 0.6.0",
+ "sysctl",
  "thiserror 2.0.12",
  "tikv-jemallocator",
  "time",
@@ -9548,6 +9561,20 @@ dependencies = [
  "syn 2.0.104",
 ]
 
+[[package]]
+name = "sysctl"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "01198a2debb237c62b6826ec7081082d951f46dbb64b0e8c7649a452230d1dfc"
+dependencies = [
+ "bitflags 2.9.1",
+ "byteorder",
+ "enum-as-inner",
+ "libc",
+ "thiserror 1.0.69",
+ "walkdir",
+]
+
 [[package]]
 name = "sysinfo"
 version = "0.36.0"