新增: MCP HTTP transport + 系统托盘 + 实体解析(会话前基线收尾)

- df-mcp 加 streamable HTTP transport 层(axum 0.7 + tower,server_http.rs),lib.rs pub mod 接线

- src-tauri 加 mcp.rs(spawn_mcp_http + mcp_get_status IPC + mcp-server CLI)+ tray.rs(系统托盘 show_main/setup_tray),lib.rs 集成 + main.rs mcp-server 参数路由

- AI 工具加 entity_resolve.rs(实体解析,tools/mod.rs pub mod 接线)

crates/df-mcp/Cargo.toml

@@ -18,6 +18,10 @@ anyhow.workspace = true
 tracing.workspace = true
 uuid.workspace = true
 futures = "0.3"
+# HTTP (streamable HTTP) transport 层:axum Router(workspace 已锁 0.7.9,零新依赖树)
+axum = { version = "0.7" }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["full", "test-util"] }
+# 单测用 tower::ServiceExt::oneshot 直接打 Router
+tower = { version = "0.5", features = ["util"] }