Fix frontend build: add lib/ to git and update Docker config

- Fix .gitignore to exclude only backend/lib/, not frontend/lib/
- Add frontend/lib/ files (api.ts, types.ts, utils.ts) to git
- Add .dockerignore to frontend to exclude build artifacts
- Update backend Dockerfile to Python 3.9 with ARM64 support
- Add debug to frontend Dockerfile
- Update claude-todo with current project state

This fixes "Module not found: Can't resolve '@/lib/api'" error
🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/lib/api.ts

@@ -0,0 +1,103 @@
+/**
+ * API client for Audio Classifier backend
+ */
+import axios from 'axios'
+import type {
+  Track,
+  TracksResponse,
+  SearchResponse,
+  SimilarTracksResponse,
+  JobStatus,
+  AnalyzeFolderRequest,
+  WaveformData,
+  Stats,
+  FilterParams,
+} from './types'
+
+const API_BASE_URL = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:8000'
+
+const apiClient = axios.create({
+  baseURL: API_BASE_URL,
+  headers: {
+    'Content-Type': 'application/json',
+  },
+})
+
+// Tracks
+export async function getTracks(params: FilterParams & { skip?: number; limit?: number }): Promise<TracksResponse> {
+  const response = await apiClient.get('/api/tracks', { params })
+  return response.data
+}
+
+export async function getTrack(id: string): Promise<Track> {
+  const response = await apiClient.get(`/api/tracks/${id}`)
+  return response.data
+}
+
+export async function deleteTrack(id: string): Promise<void> {
+  await apiClient.delete(`/api/tracks/${id}`)
+}
+
+// Search
+export async function searchTracks(
+  query: string,
+  filters?: { genre?: string; mood?: string; limit?: number }
+): Promise<SearchResponse> {
+  const response = await apiClient.get('/api/search', {
+    params: { q: query, ...filters },
+  })
+  return response.data
+}
+
+// Similar
+export async function getSimilarTracks(id: string, limit: number = 10): Promise<SimilarTracksResponse> {
+  const response = await apiClient.get(`/api/tracks/${id}/similar`, {
+    params: { limit },
+  })
+  return response.data
+}
+
+// Analysis
+export async function analyzeFolder(request: AnalyzeFolderRequest): Promise<{ job_id: string }> {
+  const response = await apiClient.post('/api/analyze/folder', request)
+  return response.data
+}
+
+export async function getAnalyzeStatus(jobId: string): Promise<JobStatus> {
+  const response = await apiClient.get(`/api/analyze/status/${jobId}`)
+  return response.data
+}
+
+export async function deleteJob(jobId: string): Promise<void> {
+  await apiClient.delete(`/api/analyze/job/${jobId}`)
+}
+
+// Audio
+export function getStreamUrl(trackId: string): string {
+  return `${API_BASE_URL}/api/audio/stream/${trackId}`
+}
+
+export function getDownloadUrl(trackId: string): string {
+  return `${API_BASE_URL}/api/audio/download/${trackId}`
+}
+
+export async function getWaveform(trackId: string, numPeaks: number = 800): Promise<WaveformData> {
+  const response = await apiClient.get(`/api/audio/waveform/${trackId}`, {
+    params: { num_peaks: numPeaks },
+  })
+  return response.data
+}
+
+// Stats
+export async function getStats(): Promise<Stats> {
+  const response = await apiClient.get('/api/stats')
+  return response.data
+}
+
+// Health
+export async function healthCheck(): Promise<{ status: string }> {
+  const response = await apiClient.get('/health')
+  return response.data
+}
+
+export default apiClient