Add ultracode toggle that runs a request as a native dynamic workflow

A new transient per-request toggle state (off→plan→ultracode→fusion→moa)
that whitelists the CLI's Workflow + Task tools so Anthropic's native
dynamic-workflow orchestration runs in gott's headless -p mode without a
permission gate (the engine silently denies Workflow otherwise). Effort is
raised to xhigh (the real ultracode equivalent; "ultracode" itself is not a
valid effort value) without downgrading an explicit max. Only enabled for
Claude models (z.ai/GLM has no workflow runtime) and not in plan mode. The
frontend injects a "use a workflow" hint, like plan mode injects its own.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

wwwroot/js/api.js

@@ -60,9 +60,10 @@ function apiMe() { return _get('/api/auth/me', null); }
 
 // ── Chat API ──
 
-function apiChat(content, sessionId, signal, planMode) {
+function apiChat(content, sessionId, signal, planMode, ultracode) {
   var payload = { content: content, sessionId: sessionId };
   if (planMode) payload.planMode = true;
+  if (ultracode) payload.ultracode = true;
   return fetch('/api/chat', { method: 'POST', headers: _jsonHeaders, body: JSON.stringify(payload), signal: signal });
 }