feat(obs): integrate dial9-tokio-telemetry for runtime tracing (#2285)

Co-authored-by: heihutu <heihutu@gmail.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

crates/obs/src/telemetry/mod.rs

@@ -39,6 +39,8 @@
 //!    initialised together with an optional stdout mirror.
 //! 3. **Stdout only** — default fallback; no file I/O, no remote export.
 
+// Dial9 module - public types are re-exported at crate level
+pub mod dial9;
 mod filter;
 mod guard;
 mod local;