fix: resolve audio stream, demuxer, and source bugs

[knownasrazi]

• WebmOpus: count processed bytes that are actually skipped so large EBML elements no longer drop real Opus frames after the tag
• streamProcessor: skip the exact ADTS frame length instead of over-skipping into the next frame when a stream starts with garbage bytes
• HLS: end the stream when a live playlist finalizes with ENDLIST and the segment queue is already empty
• DASH: resolve relative SegmentTemplate and init URLs against the MPD URL
• CrossfadeController: use independent write positions for the left/right reverb comb filters so the stereo tail stays decorrelated
• NicoVideo: parse the full ISO-8601 duration instead of only the seconds part
• Gaana: derive the AES-CBC IV from the payload instead of a static IV

[github-actions]

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[knownasrazi]

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