feat: disable actions when permissions are missing

[iret77]

Summary

• Screenshot button is disabled when Screen Recording permission is not granted, shows localized hint subtitle
• Camera button is disabled when Camera permission is not granted, shows localized hint subtitle
• Tapping a disabled action opens the relevant System Settings pane (native macOS UX)
• Chevron hidden when action is unavailable (clean visual cue)
• QuickSend and Clipboard unchanged (no TCC permission needed)
• Localized hints in all 4 languages (en/de/fr/es)

How it works

ActionMenuView now observes PermissionMonitor.shared (already registered by ContentView). Two computed properties (hasScreenRecording, hasCamera) drive both the isEnabled styling and the tap behavior.

Test plan

• Revoke Screen Recording → Screenshot shows "Grant Screen Recording to use", tapping opens Settings
• Grant Screen Recording → Screenshot works normally with chevron
• Revoke Camera → Camera shows "Grant Camera access to use", tapping opens Settings
• Grant Camera → Camera works normally
• Disconnected + no permission → both hints visible, tapping still opens Settings
• CI build passes

🤖 Generated with Claude Code