fix: 深度审计修复 — WASM 安全加固 + A2A 编译路径 + 测试编译

CRITICAL:
- zclaw_file_read: 路径遍历修复 — 组件级过滤替代前缀检查
- zclaw_http_fetch: SSRF 防护 — URL scheme 白名单 + 私有IP段阻止
- Phase 4A: 移除 zclaw-protocols a2a feature gate, A2A 始终编译
- 移除 kernel/desktop multi-agent feature (不再控制任何代码)

MEDIUM:
- user_profiler: FactCategory cfg(test) 导入修复 (563 测试全通过)

desktop/src-tauri/Cargo.toml

@@ -16,9 +16,7 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 tauri-build = { version = "2", features = [] }
 
 [features]
-default = ["multi-agent"]
-# Multi-agent orchestration (A2A protocol, Director, agent delegation)
-multi-agent = ["zclaw-kernel/multi-agent"]
+default = []
 dev-server = ["dep:axum", "dep:tower-http"]
 
 [dependencies]