fix: Distributed API UI & metrics polish + DEP0060 suppression

Add Node modal — type selector & state reset:
- Restored a Local/Remote <Select> dropdown in renderFormFields so users can
  explicitly choose the node type instead of it defaulting silently to 'remote'.
- Switching type clears api_url and api_token so no stale remote credentials
  carry over if a user switches from Remote to Local mid-form.
- Replaced the static "Add Remote Node" title with a dynamic one that reflects
  the currently selected type ("Add Local Node" / "Add Remote Node").
- onOpenChange now resets formData to defaultFormData whenever the dialog
  opens, preventing stale values from a previous session leaking in.

Remote connection details — real metrics:
- testRemoteConnection previously returned hard-coded '-' for containers,
  images, and cpus after a successful auth/check ping.
- Now fires three parallel requests (Promise.allSettled) after auth passes:
    /api/stats          → containers total + running count
    /api/system/stats   → cpu.cores
    /api/system/images  → image list length
- Each field falls back to '-' gracefully if an endpoint is unavailable,
  so a slow or older remote instance never breaks the connection test.

DEP0060 util._extend suppression:
- http-proxy@1.18.1 calls util._extend when createProxyServer() is first
  invoked at runtime (NOT at import time). A process.emitWarning override
  placed before the proxy instantiations intercepts only DEP0060 without
  suppressing any other warnings. No package version changes needed.

Also includes linter/formatter normalisation across multiple files.

frontend/src/components/SettingsModal.tsx

@@ -476,7 +476,7 @@ export function SettingsModal({ isOpen, onClose, isDarkMode, setIsDarkMode }: Se
                                         </SelectContent>
                                     </Select>
                                     {settings.developer_mode === '1' && (
-                                        <p className="text-xs text-amber-500">SSE streaming is active — polling rate is overridden by real-time streaming.</p>
+                                        <p className="text-xs text-amber-500">SSE streaming is active - polling rate is overridden by real-time streaming.</p>
                                     )}
                                 </div>
                             </div>