Use Gemini CLI Exit Codes for Robust Error Handling

[jerop]

Problem

Currently, GitHub Action has to rely on fragile string matching to detect specific error conditions from Gemini CLI output (see #205, #206). This approach is brittle and breaks when error messages change - #206 (comment).

Solution

Use exit codes once they're available in Gemini CLI - google-gemini/gemini-cli#6745.

Example usage of error codes:

Exit Code	Error Type	Action Annotation	Retry?	Cleanup Action
0	Success	None	No	Continue workflow
2	Auth Failure	::error	No	Post auth help comment
3	Rate Limit	::warning	Yes (3x)	Wait with backoff
4	Session Limit	::error	No	Post session limit comment
5	Network Issues	::warning	Yes (2x)	Retry with delay
6	Config Error	::error	No	Post config help comment
7	Permission Denied	::error	No	Post permission help comment
Other	General Failure	::error	No	Post generic error comment

[jakemac53]

@jerop looks like this is unblocked, are you actively working on it or would you like me to pick it up?

[jakemac53]

Actually nvm it looks like maybe #206 should just be directly updated

[jerop]

@jakemac53 thanks for volunteering to take this on - @leehagoodjames have you started working on updating #206 to use the error codes, or is this something @jakemac53 can help with?