fix: remove fake FLAC export format

Removed the non-standard FLAC export option which was causing import issues:

**Problem:**
- "FLAC" export was actually a custom compressed WAV format
- Used fflate (DEFLATE compression) instead of real FLAC encoding
- Files couldn't be imported back or opened in other software
- No browser-compatible FLAC encoder library exists

**Changes:**
- Removed FLAC from export format options (WAV and MP3 only)
- Removed FLAC quality slider from ExportDialog
- Removed audioBufferToFlac function reference
- Updated ExportSettings interface to only include 'wav' | 'mp3'
- Simplified bit depth selector (WAV only instead of WAV/FLAC)
- Updated format descriptions to clarify lossy vs lossless

**Export formats now:**
- ✅ WAV - Lossless, Uncompressed (16/24/32-bit)
- ✅ MP3 - Lossy, Compressed (128/192/256/320 kbps)

Users can now successfully export and re-import their audio!

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

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

components/dialogs/ExportDialog.tsx

@@ -6,11 +6,10 @@ import { Button } from '@/components/ui/Button';
 import { cn } from '@/lib/utils/cn';
 
 export interface ExportSettings {
-  format: 'wav' | 'mp3' | 'flac';
+  format: 'wav' | 'mp3';
   scope: 'project' | 'selection' | 'tracks'; // Export scope
   bitDepth: 16 | 24 | 32;
   bitrate: number; // For MP3: 128, 192, 256, 320 kbps
-  quality: number; // For FLAC: 0-9
   normalize: boolean;
   filename: string;
 }
@@ -29,7 +28,6 @@ export function ExportDialog({ open, onClose, onExport, isExporting, hasSelectio
     scope: 'project',
     bitDepth: 16,
     bitrate: 192, // Default MP3 bitrate
-    quality: 6, // Default FLAC quality
     normalize: true,
     filename: 'mix',
   });
@@ -81,13 +79,12 @@ export function ExportDialog({ open, onClose, onExport, isExporting, hasSelectio
             </label>
             <select
               value={settings.format}
-              onChange={(e) => setSettings({ ...settings, format: e.target.value as 'wav' | 'mp3' | 'flac' })}
+              onChange={(e) => setSettings({ ...settings, format: e.target.value as 'wav' | 'mp3' })}
               className="w-full px-3 py-2 bg-background border border-border rounded text-foreground focus:outline-none focus:ring-2 focus:ring-primary"
               disabled={isExporting}
             >
-              <option value="wav">WAV (Uncompressed)</option>
-              <option value="mp3">MP3 (Lossy)</option>
-              <option value="flac">FLAC (Lossless)</option>
+              <option value="wav">WAV (Lossless, Uncompressed)</option>
+              <option value="mp3">MP3 (Lossy, Compressed)</option>
             </select>
           </div>
 
@@ -115,8 +112,8 @@ export function ExportDialog({ open, onClose, onExport, isExporting, hasSelectio
             </p>
           </div>
 
-          {/* Bit Depth (WAV and FLAC only) */}
-          {(settings.format === 'wav' || settings.format === 'flac') && (
+          {/* Bit Depth (WAV only) */}
+          {settings.format === 'wav' && (
             <div>
               <label className="block text-sm font-medium text-foreground mb-2">
                 Bit Depth
@@ -167,30 +164,6 @@ export function ExportDialog({ open, onClose, onExport, isExporting, hasSelectio
             </div>
           )}
 
-          {/* FLAC Quality */}
-          {settings.format === 'flac' && (
-            <div>
-              <label className="block text-sm font-medium text-foreground mb-2">
-                Compression Quality
-              </label>
-              <div className="flex items-center gap-3">
-                <span className="text-xs text-muted-foreground">Fast</span>
-                <input
-                  type="range"
-                  min="0"
-                  max="9"
-                  value={settings.quality}
-                  onChange={(e) => setSettings({ ...settings, quality: parseInt(e.target.value) })}
-                  className="flex-1"
-                  disabled={isExporting}
-                />
-                <span className="text-xs text-muted-foreground">Small</span>
-              </div>
-              <p className="text-xs text-muted-foreground mt-1">
-                Level {settings.quality} (Higher = smaller file, slower encoding)
-              </p>
-            </div>
-          )}
 
           {/* Normalize */}
           <div>

components/editor/AudioEditor.tsx

@@ -34,7 +34,7 @@ import {
 } from '@/lib/history/commands/multi-track-edit-command';
 import { extractBufferSegment } from '@/lib/audio/buffer-utils';
 import { mixTracks, getMaxTrackDuration } from '@/lib/audio/track-utils';
-import { audioBufferToWav, audioBufferToMp3, audioBufferToFlac, downloadArrayBuffer } from '@/lib/audio/export';
+import { audioBufferToWav, audioBufferToMp3, downloadArrayBuffer } from '@/lib/audio/export';
 
 export function AudioEditor() {
   const [importDialogOpen, setImportDialogOpen] = React.useState(false);
@@ -746,16 +746,8 @@ export function AudioEditor() {
           });
           mimeType = 'audio/mpeg';
           fileExtension = 'mp3';
-        } else if (settings.format === 'flac') {
-          exportedBuffer = await audioBufferToFlac(buffer, {
-            format: 'flac',
-            bitDepth: settings.bitDepth,
-            quality: settings.quality,
-            normalize: settings.normalize,
-          });
-          mimeType = 'application/octet-stream';
-          fileExtension = 'flac';
         } else {
+          // WAV export
           exportedBuffer = audioBufferToWav(buffer, {
             format: 'wav',
             bitDepth: settings.bitDepth,