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/types.ts

@@ -0,0 +1,111 @@
+/**
+ * TypeScript type definitions for Audio Classifier
+ */
+
+export interface Track {
+  id: string
+  filepath: string
+  filename: string
+  duration_seconds: number
+  file_size_bytes: number
+  format: string
+  analyzed_at: string
+
+  features: {
+    tempo_bpm: number
+    key: string
+    time_signature: string
+    energy: number
+    danceability: number
+    valence: number
+    loudness_lufs: number
+    spectral_centroid: number
+    zero_crossing_rate: number
+  }
+
+  classification: {
+    genre: {
+      primary: string
+      secondary: string[]
+      confidence: number
+    }
+    mood: {
+      primary: string
+      secondary: string[]
+      arousal: number
+      valence: number
+    }
+    instruments: string[]
+    vocals: {
+      present: boolean | null
+      gender: string | null
+    }
+  }
+
+  embedding: {
+    model: string | null
+    dimension: number | null
+  }
+
+  metadata: Record<string, any>
+}
+
+export interface FilterParams {
+  genre?: string
+  mood?: string
+  bpm_min?: number
+  bpm_max?: number
+  energy_min?: number
+  energy_max?: number
+  has_vocals?: boolean
+  sort_by?: 'analyzed_at' | 'tempo_bpm' | 'duration_seconds' | 'filename' | 'energy'
+  sort_desc?: boolean
+}
+
+export interface TracksResponse {
+  tracks: Track[]
+  total: number
+  skip: number
+  limit: number
+}
+
+export interface SearchResponse {
+  query: string
+  tracks: Track[]
+  total: number
+}
+
+export interface SimilarTracksResponse {
+  reference_track_id: string
+  similar_tracks: Track[]
+  total: number
+}
+
+export interface JobStatus {
+  job_id: string
+  status: 'pending' | 'running' | 'completed' | 'failed'
+  progress: number
+  total: number
+  current_file: string | null
+  errors: Array<{ file?: string; error: string }>
+  saved_count?: number
+}
+
+export interface AnalyzeFolderRequest {
+  path: string
+  recursive: boolean
+}
+
+export interface WaveformData {
+  peaks: number[]
+  duration: number
+  num_peaks: number
+}
+
+export interface Stats {
+  total_tracks: number
+  genres: Array<{ genre: string; count: number }>
+  moods: Array<{ mood: string; count: number }>
+  average_bpm: number
+  total_duration_hours: number
+}