feat: integrate meshservice crate into workspace

- Add meshservice to workspace members
- Fix quicprochat-client: add MeshTrace/MeshStats slash commands
- Add integration test: meshservice_tcp_transport
- Document integration points in README and docs/status.md
- Verify shared identity (IdentityKeypair → MeshAddress)

crates/quicprochat-client/src/client/playbook.rs

@@ -434,6 +434,10 @@ impl PlaybookRunner {
             "mesh-route" => Ok(Command::MeshRoute),
             "mesh-identity" | "mesh-id" => Ok(Command::MeshIdentity),
             "mesh-store" => Ok(Command::MeshStore),
+            "mesh-trace" => Ok(Command::MeshTrace {
+                address: self.resolve_str(&step.args, "address")?,
+            }),
+            "mesh-stats" => Ok(Command::MeshStats),
 
             other => bail!("unknown command: {other}"),
         }