startup: Support $BROWSER environment variable (#890)

[Agrim863]

Added a fallback to the "GRASS_HTML_BROWSER" to support "$BROWSER" in specific environments...

[Agrim863]

Hi @susi and maintainers,

I’ve added a helper function open_browser() to handle $BROWSER and GRASS_HTML_BROWSER with proper fallback to the system default browser.

This is currently just the function; I haven’t yet replaced any existing browser calls in the code. I wanted to check if this implementation looks good and follows the project’s conventions before proceeding further.

I would appreciate any guidance on the next steps and where in the code this function should be integrated.

Thank you!

[wenzeslaus]

The code does not make much sense without context - the place where this is actually called. Even more importantly, the code does not really fit with the referenced issue. Please, review it again and be more critical towards the generated code before posting it.

[marisn]

Especially taking into account that there is already code doing browser detection. Simply existing code needs to be extended to also look into $BROWSER as one of candidates.