- Introduced `CountTokens` method to Codex, Claude, Gemini, Qwen, OpenAI-compatible, and other executors.
- Implemented `ExecuteCount` in `AuthManager` for token counting via provider round-robin.
- Updated handlers to leverage `ExecuteCountWithAuthManager` for streamlined token counting.
- Added fallback and error handling logic for token counting requests.
- Introduced `EnsureHeader` in `internal/misc/header_utils.go` to streamline header setting across executors.
- Updated Codex, Claude, and Gemini executors to utilize `EnsureHeader` for consistent header application.
- Incorporated Gin context headers (if available) into request header manipulation for better integration.
- Added detailed debug logs in all executors (Codex, Claude, Gemini, Qwen, OpenAI-compatible) to capture HTTP status and response body for failed API requests.
- Added `last_refresh` timestamp to metadata for Codex, Claude, Qwen, and Gemini executors.
- Implemented `extractLastRefreshTimestamp` utility for parsing diverse timestamp formats in management handlers.
- Ensured consistent update and preservation of `last_refresh` in file-based auth handling.
- Introduced `logrus` for structured debugging across all executors.
- Added debug log messages in `Refresh` methods for better traceability.
- Updated `Manager` to log additional details during refresh checks.
- Added `Refresh` method implementations for Codex, Claude, Gemini, and Qwen executors.
- Introduced OAuth-based token handling for Gemini and Qwen with support for refresh tokens.
- Updated Codex and Claude to use new internal auth services.
- Enhanced metadata structure and consistency for token storage across all executors.
- Renamed constants from uppercase to CamelCase for consistency.
- Replaced redundant file-based auth handling logic with the new `util.CountAuthFiles` helper.
- Fixed various error-handling inconsistencies and enhanced robustness in file operations.
- Streamlined auth client reload logic in server and watcher components.
- Applied minor code readability improvements across multiple packages.
