feat(web): skills API types + client methods

apps/web/src/api/client.ts

@@ -10,6 +10,7 @@ import type {
   ViewFileResult,
   AgentsResponse,
   GitMeta,
+  Skill,
 } from './types';
 
 export class ApiError extends Error {
@@ -187,6 +188,20 @@ export const api = {
         method: 'POST',
         body: JSON.stringify({ message_id: body.messageId, name: body.name }),
       }),
+    // Batch 9.6: slash-command invocation. Server loads the skill body
+    // authoritatively (client doesn't get to forge file contents), persists
+    // a synthetic skill_use tool_use + tool_result + user message + streaming
+    // assistant, and enqueues inference. Returns all 4 new message IDs.
+    skillInvoke: (chatId: string, skillName: string, userMessage: string | null) =>
+      request<{
+        synth_assistant_id: string;
+        tool_message_id: string;
+        user_message_id: string;
+        assistant_message_id: string;
+      }>(`/api/chats/${chatId}/skill_invoke`, {
+        method: 'POST',
+        body: JSON.stringify({ skill_name: skillName, user_message: userMessage }),
+      }),
   },
 
   messages: {
@@ -218,6 +233,10 @@ export const api = {
       request<AgentsResponse>(`/api/projects/${projectId}/agents`),
   },
 
+  skills: {
+    list: () => request<{ skills: Skill[] }>('/api/skills'),
+  },
+
   settings: {
     get: () => request<Record<string, unknown>>('/api/settings'),
     patch: (body: Record<string, unknown>) =>