feat: Add `--verbose` / `--debug` CLI Flags

[yokoszn]

Closes #144

Summary

• Add -v/--verbose flag (stackable: -v, -vv, -vvv) for increasing log verbosity
• Add --debug flag as shortcut for maximum verbosity (-vvv)
• Logs output to both stderr and strix_runs/{run_name}/debug.log when verbosity > 0
• At -vvv/--debug, enables litellm verbose mode for LLM debugging

Behavior

Flag	Level	stderr	File
(none)	ERROR	yes	no
-v	WARNING	yes	yes
-vv	INFO	yes	yes
-vvv / --debug	DEBUG	yes	yes

Implementation Notes

• Removed conflicting global logging.getLogger().setLevel(logging.ERROR)
• Uses logging.basicConfig(force=True) to ensure configuration is applied
• Uses litellm._logging._enable_debugging() for correct litellm debug toggle
• Log file created in run directory after run name is generated

Other Considerations

Log Rotation / Max Size

• Current implementation appends to debug.log indefinitely
• Could add rotation or size limits for long-running sessions in future PR

Colored Log Output

• Could use rich for colored stderr logging
• Would improve readability in terminal

[x676f64]

While this is maybe a start, the output is really ugly and breaks the TUI. It also doesn't show the HTTP request body or response body in the output.