fix(audit): 修复深度审计 P2 问题 — 自主授权后端守卫、反思历史累积、心跳持久化

- M5-补: hand_execute/skill_execute 接收 autonomy_level 参数，后端三层守卫
  (supervised 全部审批 / assisted 尊重 needs_approval / autonomous 跳过)
- M3: hand_approve/hand_cancel 移除 _hand_name 下划线，添加审计日志
- M4-补: 反思历史累积存储到 reflection:history:{agent_id} 数组(最多20条)
  get_history 优先读持久化历史，保留 latest key 向后兼容
- 心跳历史: VikingStorage 持久化 HeartbeatResult 数组，tick() 也存历史
  heartbeat_init 恢复历史，重启后不丢失
- L2: 确认 gatewayStore 仅注释引用，无需修改
- 身份回滚: 确认 IdentityChangeProposal.tsx 已实现 HistoryItem + restoreSnapshot
- 更新 DEEP_AUDIT_REPORT.md 完成度 72% (核心 92%, 真实可用 80%)

desktop/src/lib/kernel-client.ts

@@ -684,10 +684,11 @@ export class KernelClient {
   /**
    * Trigger/execute a hand
    */
-  async triggerHand(name: string, params?: Record<string, unknown>): Promise<{ runId: string; status: string }> {
+  async triggerHand(name: string, params?: Record<string, unknown>, autonomyLevel?: string): Promise<{ runId: string; status: string }> {
     const result = await invoke<{ instance_id: string; status: string }>('hand_execute', {
       id: name,
       input: params || {},
+      ...(autonomyLevel ? { autonomyLevel } : {}),
     });
     return { runId: result.instance_id, status: result.status };
   }
@@ -810,6 +811,8 @@ export class KernelClient {
 
   /**
    * Execute a skill
+   * Checks autonomy authorization before execution and passes the autonomy
+   * level to the backend for defense-in-depth enforcement.
    */
   async executeSkill(id: string, input?: Record<string, unknown>): Promise<{
     success: boolean;
@@ -817,10 +820,23 @@ export class KernelClient {
     error?: string;
     durationMs?: number;
   }> {
+    // Autonomy check before executing skill
+    const { canAutoExecute, getAutonomyManager } = await import('./autonomy-manager');
+    const { canProceed, decision } = canAutoExecute('skill_install', 5);
+    if (!canProceed) {
+      return {
+        success: false,
+        error: `自主授权拒绝: ${decision.reason}`,
+      };
+    }
+
+    const autonomyLevel = getAutonomyManager().getConfig().level;
+
     return invoke('skill_execute', {
       id,
       context: {},
       input: input || {},
+      autonomyLevel,
     });
   }