Memory-efficient streaming for long Omi device recordings

[unforced]

Problem

Currently, audio frames accumulate in memory during Omi device recordings. For very long recordings (>30 minutes), this could cause memory pressure or OOM errors.

Location: lib/utils/audio/wav_bytes_util.dart:16-17

List<List<int>> frames = [];
List<List<int>> rawPackets = [];

Suggested Solution

Implement one of the following approaches:

1. Streaming to disk: Write frames to temporary file during recording

   static const int MAX_FRAMES_IN_MEMORY = 1000; // ~30 seconds at 16kHz
   if (frames.length > MAX_FRAMES_IN_MEMORY) {
     _flushToTemporaryFile();
   }

2. Circular buffer: Keep only recent frames in memory and stream older ones

3. Chunked processing: Process and write audio in chunks during recording

Benefits

• Prevents OOM errors for long recordings
• Reduces memory footprint
• Enables unlimited recording length

Priority

Medium - Only affects edge cases (very long recordings)

Related

• Part of PR #8 review feedback
• See lib/utils/audio/wav_bytes_util.dart for current implementation