feat: add live model and thinking option preferences UI (#8)

* feat: add live model and thinking option preferences UI

* refactor: remove agent variant support and clean up thinking options

* feat: live model + thinking presets (RPC)

packages/app/src/utils/agent-initialization.ts

@@ -0,0 +1,44 @@
+export interface DeferredInit {
+  promise: Promise<void>;
+  resolve: () => void;
+  reject: (error: Error) => void;
+}
+
+const initPromises = new Map<string, DeferredInit>();
+
+export function getInitKey(serverId: string, agentId: string): string {
+  return `${serverId}:${agentId}`;
+}
+
+export function getInitDeferred(key: string): DeferredInit | undefined {
+  return initPromises.get(key);
+}
+
+export function createInitDeferred(key: string): DeferredInit {
+  let resolve!: () => void;
+  let reject!: (error: Error) => void;
+
+  const promise = new Promise<void>((res, rej) => {
+    resolve = res;
+    reject = rej;
+  });
+
+  const deferred: DeferredInit = { promise, resolve, reject };
+  initPromises.set(key, deferred);
+  return deferred;
+}
+
+export function resolveInitDeferred(key: string): void {
+  const deferred = initPromises.get(key);
+  deferred?.resolve();
+}
+
+export function rejectInitDeferred(key: string, error: Error): void {
+  const deferred = initPromises.get(key);
+  if (!deferred) {
+    return;
+  }
+  initPromises.delete(key);
+  deferred.reject(error);
+}
+