fix(pusher): improve welist response logging, error handling, and add request timeout

- Always log HTTP status code and response body from welist (info level)
- Log send_stats_report errors at call site instead of silently discarding
- Add 10s timeout to reqwest client to prevent indefinite hangs
- Apply clippy fixes (is_empty, if-let chains, dead_code, etc.)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bal_server"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html