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/codex.js

@@ -22,7 +22,8 @@ const SERVER_ID_PATTERN = /^(rs|fc|resp|msg)_/;
 // Hosted tool types that Codex/OpenAI Responses executes server-side
 const CODEX_HOSTED_TOOL_TYPES = new Set([
   "image_generation", "web_search", "web_search_preview", "file_search",
-  "computer", "computer_use_preview", "code_interpreter", "mcp", "local_shell"
+  "computer", "computer_use_preview", "code_interpreter", "mcp", "local_shell",
+  "tool_search"
 ]);
 
 // Allowlist of fields accepted by Codex Responses API — anything else is stripped