feat(headroom): add proxy lifecycle management + dashboard UI

Build on the optional Headroom Token Saver from Carmelo Campos
(PR: feat: add optional Headroom token saver). Add managed start/stop
of the local headroom proxy from the dashboard, install detection,
status probing, and a simplified Token Saver UI.

- detect headroom CLI + python>=3.10, probe proxy /health
- spawn/stop proxy as a detached, pid-tracked process
- /api/headroom/{status,start,stop} routes, gated local-only in dashboardGuard
- one-click Start/Stop Headroom modal, no manual config needed
- claude<->openai shape conversion for /v1/compress via 9router translators

Thanks to Carmelo Campos (@carmelogunsroses) for the original Headroom integration.

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/executors/xiaomi-tokenplan.js

@@ -8,13 +8,13 @@ export class XiaomiTokenplanExecutor extends DefaultExecutor {
     super("xiaomi-tokenplan");
   }
 
-  // Token Plan keys are region-specific — always OpenAI-compatible /chat/completions
+  // Token Plan keys are region-specific. Route per sourceFormat-matched transport:
+  // claude → Anthropic /anthropic/v1/messages, openai → /chat/completions.
   buildUrl(model, stream, urlIndex = 0, credentials = null) {
     const baseUrl = resolveXiaomiTokenplanBaseUrl(credentials);
-    // Claude-native aliases route to the Anthropic-compatible messages endpoint
-    // if (getModelTargetFormat(this.provider, model) === FORMATS.CLAUDE) {
-    //   return `${baseUrl.replace(/\/v1\/?$/, "/anthropic/v1")}/messages`;
-    // }
+    if (credentials?.runtimeTransport?.format === "claude") {
+      return `${baseUrl.replace(/\/v1\/?$/, "")}/anthropic/v1/messages`;
+    }
     return `${baseUrl}/chat/completions`;
   }
 }