fix(frontend): Add comprehensive debug logging for Epic creation

Add detailed console logging to diagnose Epic creation issue where
no request is being sent to backend.

Changes:
- Add form submission event logging in epic-form.tsx
- Add API request/response logging in epicsApi.create
- Add HTTP client interceptor logging for all requests/responses
- Log authentication status, payload, and error details
- Log form validation state and errors

This will help identify:
- Whether form submit event fires
- Whether validation passes
- Whether API call is triggered
- Whether authentication token exists
- What errors occur (if any)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/api/client.ts

@@ -49,9 +49,18 @@ apiClient.interceptors.request.use(
     if (token) {
       config.headers.Authorization = `Bearer ${token}`;
     }
+    console.log('[API] Request:', {
+      method: config.method?.toUpperCase(),
+      url: config.url,
+      hasAuth: !!token,
+      data: config.data,
+    });
     return config;
   },
-  (error) => Promise.reject(error)
+  (error) => {
+    console.error('[API] Request interceptor error:', error);
+    return Promise.reject(error);
+  }
 );
 
 // Response interceptor: automatically refresh Token
@@ -74,8 +83,22 @@ const processQueue = (error: unknown, token: string | null = null) => {
 };
 
 apiClient.interceptors.response.use(
-  (response) => response,
+  (response) => {
+    console.log('[API] Response:', {
+      status: response.status,
+      url: response.config.url,
+      data: response.data,
+    });
+    return response;
+  },
   async (error: AxiosError) => {
+    console.error('[API] Response error:', {
+      status: error.response?.status,
+      url: error.config?.url,
+      message: error.message,
+      data: error.response?.data,
+    });
+
     const originalRequest = error.config as InternalAxiosRequestConfig & {
       _retry?: boolean;
     };

lib/api/pm.ts

@@ -26,7 +26,15 @@ export const epicsApi = {
   },
 
   create: async (data: CreateEpicDto): Promise<Epic> => {
-    return api.post('/api/v1/epics', data);
+    console.log('[epicsApi.create] Sending request', { url: '/api/v1/epics', data });
+    try {
+      const result = await api.post('/api/v1/epics', data);
+      console.log('[epicsApi.create] Request successful', result);
+      return result;
+    } catch (error) {
+      console.error('[epicsApi.create] Request failed', error);
+      throw error;
+    }
   },
 
   update: async (id: string, data: UpdateEpicDto): Promise<Epic> => {