fix: use lamejs Mp3Encoder API for proper module initialization

Switched from low-level Lame API to Mp3Encoder class which:
- Properly initializes all required modules (Lame, BitStream, etc.)
- Handles module dependencies via setModules() calls
- Provides a simpler encodeBuffer/flush API
- Resolves "init_bit_stream_w is not defined" error

Updated TypeScript declarations to export Mp3Encoder and WavHeader
from lamejs/src/js/index.js

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

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

types/lamejs.d.ts

@@ -1,31 +1,15 @@
-declare module 'lamejs/src/js/MPEGMode' {
-  const MPEGMode: {
-    STEREO: number;
-    JOINT_STEREO: number;
-    DUAL_CHANNEL: number;
-    MONO: number;
-    NOT_SET: number;
-  };
-  export default MPEGMode;
-}
+declare module 'lamejs/src/js/index.js' {
+  export class Mp3Encoder {
+    constructor(channels: number, samplerate: number, kbps: number);
+    encodeBuffer(left: Int16Array, right: Int16Array): Int8Array;
+    flush(): Int8Array;
+  }
 
-declare module 'lamejs/src/js/Lame' {
-  export default class Lame {
-    lame_init(): any;
-    lame_init_params(gfp: any): number;
-    lame_encode_buffer(
-      gfp: any,
-      left: Int16Array,
-      right: Int16Array,
-      samples: number,
-      mp3buf: Int8Array,
-      mp3bufPos: number
-    ): number;
-    lame_encode_flush(gfp: any, mp3buf: Int8Array, mp3bufPos: number): number;
-    lame_close(gfp: any): number;
+  export class WavHeader {
+    dataOffset: number;
+    dataLen: number;
+    channels: number;
+    sampleRate: number;
+    static readHeader(dataView: DataView): WavHeader;
   }
 }
-
-declare module 'lamejs/src/js/BitStream' {
-  export default class BitStream {}
-}