Add runner capabilities display to web UI

- Display capabilities on runner edit page (OS, Docker, shells, tools)
- Add locale translations for capability labels
- Parse and render CapabilitiesJSON from runner model
- Update actions-proto-go to v0.5.2

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

options/locale/locale_en-US.json

@@ -3696,6 +3696,13 @@
   "actions.runners.reset_registration_token": "Reset registration token",
   "actions.runners.reset_registration_token_confirm": "Would you like to invalidate the current token and generate a new one?",
   "actions.runners.reset_registration_token_success": "Runner registration token reset successfully",
+  "actions.runners.capabilities": "Capabilities",
+  "actions.runners.capabilities.os": "OS/Arch",
+  "actions.runners.capabilities.docker": "Docker",
+  "actions.runners.capabilities.shells": "Shells",
+  "actions.runners.capabilities.tools": "Tools",
+  "actions.runners.capabilities.limitations": "Limitations",
+  "actions.runners.capabilities.available": "Available",
   "actions.runs.all_workflows": "All Workflows",
   "actions.runs.commit": "Commit",
   "actions.runs.scheduled": "Scheduled",