fix(lint): resolve 35 clippy warnings across Rust codebase

Fix all clippy warnings reported by `cargo clippy --lib`:

- codex_config.rs: fix doc_overindented_list_items (3 spaces -> 2)
- commands/copilot.rs: inline format args in 2 log::error! calls
- commands/provider.rs: inline format args in 3 map_err closures
- proxy/hyper_client.rs: inline format arg in log::debug! call
- proxy/providers/copilot_auth.rs: inline format args in 16 locations
  (log macros, format! in headers, error constructors)
- proxy/thinking_optimizer.rs: inline format args in 2 log::info! calls
- services/skill.rs: inline format args in log::debug! call
- services/webdav_sync.rs: inline format args in 6 format! calls
  (version compat messages, download limit messages)
- services/webdav_sync/archive.rs: inline format args in 2 format! calls
- session_manager/providers/opencode.rs: inline format args in
  source_path format!

All fixes use the clippy::uninlined_format_args suggestion pattern:
  format!("msg: {}", var)  ->  format!("msg: {var}")

src-tauri/src/services/webdav_sync/archive.rs

@@ -350,8 +350,8 @@ fn copy_entry_with_total_limit<R: Read, W: Write>(
             let max_mb = max_total_bytes / 1024 / 1024;
             return Err(localized(
                 "webdav.sync.skills_zip_too_large",
-                format!("skills.zip 解压后体积超过上限（{} MB）", max_mb),
-                format!("skills.zip extracted size exceeds limit ({} MB)", max_mb),
+                format!("skills.zip 解压后体积超过上限（{max_mb} MB）"),
+                format!("skills.zip extracted size exceeds limit ({max_mb} MB)"),
             ));
         }