plugins: add SourceOS plugin (workstation shortcuts)

[mdheller]

Adds a new in-tree plugin under plugins/sourceos.

The plugin provides a small set of SourceOS workstation shortcuts via a triggered query handler (default trigger: sourceos ). It integrates with the local SourceOS CLI when available and exposes common developer tools as selectable items.

Follow-ups will extend the command set and add optional configuration UI.

[mdheller]

Update: expanded the SourceOS plugin actions and aligned them to the installed sourceos helper CLI.

• Plugin now calls:

  • sourceos doctor
  • sourceos profile apply

• Added quick-launch actions for: sesh, tmux, k9s, lazygit, lazydocker, yazi.

This matches the workstation profile changes in SociOS-Linux/source-os where sourceos is installed into ~/.local/bin.

[mdheller]

Update: plugin now uses launcher-friendly report commands.

• SourceOS: status runs sourceos status --open (writes JSON to cache and opens it)
• SourceOS: doctor runs sourceos doctor --open (writes doctor output to cache and opens it)

This removes the need for a terminal window just to read output, and matches the new sourceos status surface added in SociOS-Linux/source-os PR albertlauncher#33.