feat(web): expose Pi thinking state

web/host/web-host.ts

@@ -557,6 +557,11 @@ export class WebHost {
     }
     if (url.pathname === "/api/models")
       return this.json(response, 200, { models: this.runtime.listModels() });
+    if (url.pathname === "/api/thinking")
+      return this.json(response, 200, {
+        sessionId: this.runtime.sessionManager.getSessionId(),
+        ...(this.runtime.getThinkingState?.() ?? { level: "unknown", available: [] }),
+      });
     if (url.pathname === "/api/snapshot") {
       const cursor = this.sequence;
       const projection = await this.adapter.getSnapshot(

web/runtime/pi-runtime.ts

@@ -265,6 +265,11 @@ export class PiWebRuntime implements WebRuntimeController {
     return () => this.listeners.delete(listener);
   }
 
+  getThinkingState() {
+    const session = this.runtime.session;
+    return { level: session.thinkingLevel, available: session.getAvailableThinkingLevels() };
+  }
+
   async sendPrompt(content: string, options?: WebPromptOptions) {
     this.assertActive();
     this.assertWorkspaceSelected();

web/runtime/types.ts

@@ -61,6 +61,7 @@ export interface WebRuntimeController {
   ): Promise<WebSessionCreationResult>;
   switchSession(sessionPath: string): Promise<{ cancelled: boolean }>;
   listModels(): WebModelSummary[];
+  getThinkingState?(): { level: string; available: readonly string[] };
   setModel(
     provider: string,
     modelId: string,