fix(growth,hands,kernel,desktop): Phase 1 用户可感知修复 — 6 项断链修复

Phase 1 修复内容:
1. Hand 执行前端字段映射 — instance_id → runId，修复 Hand 状态追踪
2. Heartbeat 痛点感知 — PAIN_POINTS_CACHE + VikingStorage 持久化 + 未解决痛点检查
3. Browser Hand 委托消息 — pending_execution → delegated_to_frontend + 中文摘要
4. 跨会话记忆检索增强 — 扩展 IdentityRecall 模式 26→43 + 弱身份信号检测 + 低结果 fallback
5. Twitter Hand 凭据持久化 — SetCredentials action + 文件持久化 + 启动恢复
6. Browser 测试修复 — 适配新的 delegated_to_frontend 响应格式

验证: cargo check ✅ | cargo test 912 PASS ✅ | tsc --noEmit ✅

desktop/src/lib/gateway-api.ts

@@ -380,10 +380,14 @@ export function installApiMethods(ClientClass: { prototype: GatewayClient }): vo
   proto.triggerHand = async function (this: GatewayClient, name: string, params?: Record<string, unknown>): Promise<{ runId: string; status: string }> {
     try {
       const result = await this.restPost<{
-        instance_id: string;
-        status: string;
+        success: boolean;
+        run_id?: string;
+        output?: { status?: string };
       }>(`/api/hands/${name}/activate`, params || {});
-      return { runId: result.instance_id, status: result.status };
+      return {
+        runId: result.run_id || '',
+        status: result.output?.status || (result.success ? 'completed' : 'failed'),
+      };
     } catch (err) {
       logger.error(`Hand trigger failed for ${name}`, { error: err });
       throw err;

desktop/src/lib/kernel-hands.ts

@@ -91,19 +91,21 @@ export function installHandMethods(ClientClass: { prototype: KernelClient }): vo
    * Trigger/execute a hand
    */
   proto.triggerHand = async function (this: KernelClient, name: string, params?: Record<string, unknown>, autonomyLevel?: string): Promise<{ runId: string; status: string }> {
-    const result = await invoke<{ instance_id: string; status: string }>('hand_execute', {
+    const result = await invoke<{ success: boolean; runId?: string; output?: { status?: string }; error?: string }>('hand_execute', {
       id: name,
       input: params || {},
       ...(autonomyLevel ? { autonomyLevel } : {}),
     });
+    const runId = result.runId || '';
+    const status = result.output?.status || (result.success ? 'completed' : 'failed');
     // P2-25: Audit hand execution
     try {
       const { logSecurityEvent } = await import('./security-audit');
-      logSecurityEvent('hand_executed', `Hand "${name}" executed (runId: ${result.instance_id}, status: ${result.status})`, {
-        handId: name, runId: result.instance_id, status: result.status, autonomyLevel,
+      logSecurityEvent('hand_executed', `Hand "${name}" executed (runId: ${runId}, status: ${status})`, {
+        handId: name, runId, status, autonomyLevel,
       });
     } catch { /* audit failure is non-blocking */ }
-    return { runId: result.instance_id, status: result.status };
+    return { runId, status };
   };
 
   /**