feat(gateway): 新增 /api/tools 与 /api/subagents/update 端点

- /api/tools: 只读访问 ToolRegistry，返回 builtin + MCP 工具的 name/description/source

- /api/subagents/update: PUT 接口，调用 SubagentRuntime::update_subagent 写回 SUBAGENT.md frontmatter

- 路由表两处同步注册新端点

src/gateway/http.rs

@@ -5,6 +5,7 @@ use std::sync::Arc;
 
 use super::GatewayState;
 use crate::config::{Config, get_default_config_path};
+use crate::domain::CapabilityPolicy;
 use crate::experts::{Expert, ExpertScope, ExpertWithStatus};
 use crate::skills::SkillWithStatus;
 use crate::tools::task::runtime::{SubagentScope, SubagentWithStatus};
@@ -248,6 +249,52 @@ pub async fn skills_list(
     })
 }
 
+#[derive(Serialize)]
+pub struct ToolInfo {
+    pub name: String,
+    pub description: String,
+    /// "builtin" 或 "mcp:{server_key}"
+    pub source: String,
+}
+
+#[derive(Serialize)]
+pub struct ToolsListResponse {
+    pub total: usize,
+    pub tools: Vec<ToolInfo>,
+}
+
+/// GET /api/tools — Return all registered tools (builtin + MCP) with name/description/source.
+/// 通过 SessionManager::tools() 只读访问 ToolRegistry，不修改状态。
+pub async fn tools_list(
+    State(state): State<Arc<GatewayState>>,
+) -> Json<ToolsListResponse> {
+    let registry = state.session_manager.tools();
+    let tools: Vec<ToolInfo> = registry
+        .get_definitions()
+        .into_iter()
+        .map(|t| {
+            let source = if t.function.name.starts_with("mcp_") {
+                // mcp_{server}_{tool} → mcp:{server}
+                let parts: Vec<&str> = t.function.name.splitn(3, '_').collect();
+                if parts.len() == 3 {
+                    format!("mcp:{}", parts[1])
+                } else {
+                    "mcp".to_string()
+                }
+            } else {
+                "builtin".to_string()
+            };
+            ToolInfo {
+                name: t.function.name,
+                description: t.function.description,
+                source,
+            }
+        })
+        .collect();
+    let total = tools.len();
+    Json(ToolsListResponse { total, tools })
+}
+
 /// POST /api/skills/toggle — Enable or disable a specific skill
 pub async fn skills_toggle(
     State(state): State<Arc<GatewayState>>,
@@ -423,6 +470,69 @@ pub async fn subagents_toggle(
     }
 }
 
+#[derive(Deserialize)]
+pub struct SubagentUpdateRequest {
+    pub name: String,
+    pub description: Option<String>,
+    pub body: Option<String>,
+    #[serde(default)]
+    pub capability: Option<CapabilityPolicy>,
+}
+
+#[derive(Serialize)]
+pub struct SubagentUpdateResponse {
+    pub success: bool,
+    pub subagent: Option<SubagentWithStatus>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+/// PUT /api/subagents/update — Update subagent capability/description/body (writes back SUBAGENT.md)
+pub async fn subagents_update(
+    State(state): State<Arc<GatewayState>>,
+    Json(req): Json<SubagentUpdateRequest>,
+) -> Result<Json<SubagentUpdateResponse>, (StatusCode, String)> {
+    let updated = state
+        .subagent_runtime
+        .update_subagent(
+            &req.name,
+            req.description.as_deref(),
+            req.body.as_deref(),
+            req.capability.as_ref(),
+            true,
+        )
+        .map_err(|err| {
+            let status = if err.contains("not found") {
+                StatusCode::NOT_FOUND
+            } else if err.contains("builtin") {
+                StatusCode::BAD_REQUEST
+            } else {
+                StatusCode::INTERNAL_SERVER_ERROR
+            };
+            (status, err)
+        })?;
+
+    // 返回更新后的状态（含 disabled_in_scopes）
+    let status = state
+        .subagent_runtime
+        .list_with_status()
+        .into_iter()
+        .find(|s| s.name == updated.name)
+        .unwrap_or_else(|| SubagentWithStatus {
+            name: updated.name.clone(),
+            description: updated.description.clone(),
+            source: updated.source.as_str().to_string(),
+            disabled_in_scopes: vec![],
+            capability: updated.capability.clone(),
+        });
+
+    Ok(Json(SubagentUpdateResponse {
+        success: true,
+        subagent: Some(status),
+        error: None,
+    }))
+}
+
 // ===================== Experts =====================
 
 #[derive(Deserialize)]
@@ -458,6 +568,8 @@ pub struct ExpertCreateRequest {
     pub description: String,
     pub body: String,
     pub scope: String,
+    #[serde(default)]
+    pub capability: CapabilityPolicy,
 }
 
 #[derive(Deserialize)]
@@ -466,6 +578,8 @@ pub struct ExpertUpdateRequest {
     pub scope: String,
     pub description: Option<String>,
     pub body: Option<String>,
+    #[serde(default)]
+    pub capability: Option<CapabilityPolicy>,
 }
 
 #[derive(Deserialize)]
@@ -505,6 +619,8 @@ pub struct ExpertResponse {
     pub body: String,
     pub source: String,
     pub path: String,
+    #[serde(default)]
+    pub capability: CapabilityPolicy,
 }
 
 impl From<Expert> for ExpertResponse {
@@ -515,6 +631,7 @@ impl From<Expert> for ExpertResponse {
             body: expert.body,
             source: expert.source.as_str().to_string(),
             path: expert.path.display().to_string(),
+            capability: expert.capability,
         }
     }
 }
@@ -625,7 +742,7 @@ pub async fn experts_create(
 
     let expert = state
         .experts
-        .create_expert(scope, &req.name, &req.description, &req.body, true)
+        .create_expert(scope, &req.name, &req.description, &req.body, &req.capability, true)
         .map_err(|err| {
             let status = if err.contains("already exists") {
                 StatusCode::CONFLICT
@@ -653,6 +770,7 @@ pub async fn experts_update(
             &req.name,
             req.description.as_deref(),
             req.body.as_deref(),
+            req.capability.as_ref(),
             true,
         )
         .map_err(|err| {

src/gateway/mod.rs

@@ -241,8 +241,10 @@ pub async fn run(
             .route("/api/mcp/status", routing::get(http::mcp_status))
             .route("/api/skills", routing::get(http::skills_list))
             .route("/api/skills/toggle", routing::post(http::skills_toggle))
+            .route("/api/tools", routing::get(http::tools_list))
             .route("/api/subagents", routing::get(http::subagents_list))
             .route("/api/subagents/toggle", routing::post(http::subagents_toggle))
+            .route("/api/subagents/update", routing::put(http::subagents_update))
             .route("/api/experts", routing::get(http::experts_list))
             .route("/api/experts/toggle", routing::post(http::experts_toggle))
             .route("/api/experts/create", routing::post(http::experts_create))
@@ -262,8 +264,10 @@ pub async fn run(
             .route("/api/mcp/status", routing::get(http::mcp_status))
             .route("/api/skills", routing::get(http::skills_list))
             .route("/api/skills/toggle", routing::post(http::skills_toggle))
+            .route("/api/tools", routing::get(http::tools_list))
             .route("/api/subagents", routing::get(http::subagents_list))
             .route("/api/subagents/toggle", routing::post(http::subagents_toggle))
+            .route("/api/subagents/update", routing::put(http::subagents_update))
             .route("/api/experts", routing::get(http::experts_list))
             .route("/api/experts/toggle", routing::post(http::experts_toggle))
             .route("/api/experts/create", routing::post(http::experts_create))