Shell context menu integration

[cst8t]

Why this matters

A lot of Git actions start before the repo is even open in an app. Being able to right-click a folder, repo, or remote URL and jump straight into Gitmun would make common workflows feel much more natural.

What this should cover

• Add shell context menu integration on supported platforms
• Support useful entry points like:
  • clone into Gitmun
  • open repo in Gitmun
  • fetch
  • pull
  • push
• Make actions appear in places that make sense, such as folders, repositories, and maybe selected files where relevant
• Keep labels and behavior consistent across platforms, while still respecting platform conventions
• Handle cases where Gitmun is not running already
• Make failures more understandable when the selected path is not a repo, Git is unavailable, or the requested action cannot run safely
• Leave room for platform-specific expansion later without making the first version overly broad

Done when

• You can right-click a supported path and launch useful Gitmun actions from the shell
• Opening or cloning from the context menu feels reliable and fast
• Repo actions only show up when they make sense for the selected target
• Platform differences do not make the feature feel confusing or half-broken
• If an action cannot run, Gitmun explains why instead of failing silently

Notes

This should feel like Gitmun showing up where Git work already starts, not just bolting a few commands onto the shell.

[cst8t]

Gonna integrate the cli stuff but gonna shelf this for the time being as think (with further investigation) context menu support will probably need its own package to support different distros handling etc. Keeping them seperate will be easier to manage and then they just use the cli stuff exposed by Gitmun but need to do more research on that