- Replace fmt.Fprintf/os.Stderr with centralized debuglog.Log across CLI
- Add unconditional Log function to debuglog for important messages
- Improve OAuth flow messaging and token refresh diagnostics
- Update tests to capture debuglog output via SetOutput
- Convert Perplexity streaming errors to unified debug logging
- Emit file write notifications through debuglog instead of stderr
- Warn on ambiguous model selection using centralized logger
- Announce large audio processing steps via debuglog progress messages
- Standardize extension registry and patterns warnings through debuglog