workstation-v0 aggregate polish doctor integration

[mdheller]

Closes #120.

What changed:

• Integrated check-workstation-polish.sh into profiles/linux-dev/workstation-v0/doctor.sh.
• Added warning-oriented doctor results for Mac polish and keyboard policy aggregate signals.
• Added workstation-doctor-polish smoke workflow for doctor JSON shape and warning-only behavior.

Validation evidence:

• bash -n profiles/linux-dev/workstation-v0/doctor.sh
• bash profiles/linux-dev/workstation-v0/doctor.sh --json
• workflow smoke validates kind, profile, summary, and results shape
• workflow smoke validates invalid aggregate keyboard policy emits warning result without changing doctor JSON shape

Known gaps:

• This does not change sourceos status; that was handled separately.

Non-goals preserved:

• No Lampstand implementation changes.
• No package manifest changes.
• No GNOME appearance defaults changed.
• No keyboard/remap installer behavior changed.