workstation-v0: extend aggregate polish helper with dock and shortcut signals

[Copilot]

The aggregate polish helper (check-workstation-polish.sh) only consumed mac_polish and keyboard_policy sections, leaving shortcut_map and gnome_dock signals absent from the single aggregation surface needed by downstream status/doctor work.

Changes

• check-workstation-polish.sh — two additional emit_section calls in main():

  emit_section shortcut_map "$pdir/bin/check-shortcut-map-contract.sh"
  emit_section gnome_dock    "$pdir/bin/check-gnome-dock-extension.sh"

  Follows the existing pattern exactly; no changes to emit_section itself.

• workstation-polish-validation.yml

  • Adds both new helpers to paths: triggers (pull_request + push).
  • Adds bash -n syntax checks for the two new helpers.
  • Adds smoke assertions for shortcut_map.helper=present, shortcut_map.shortcut_map=, gnome_dock.helper=present, and gnome_dock.gnome_dock_extension_lane_ok=.

[mdheller]

Supersession review:

This PR is being closed in favor of #146.

Reason: #146 preserves the same aggregate-polish intent from this PR and additionally fixes the check-shortcut-map-contract.sh repo-root traversal bug. Keeping both open creates a stale duplicate lane for the same workstation-v0 aggregate polish work.

Useful content from this PR is represented in #146:

• add shortcut_map and gnome_dock sections to check-workstation-polish.sh;
• extend the workstation polish workflow path filters;
• add syntax checks for shortcut/dock helpers;
• assert aggregate shortcut_map.* and gnome_dock.* outputs.

Action: close this PR as superseded; continue with #146 or replay #146 onto a fresh branch if current main has moved too far.