- optimize codebook list (section_data) via joint/DP optimization
- optimize CPE windows grouping jointly across channel pairs
- Add adaptive bit reservoir control
- add PCE (Program Config Element) or 4-bit AudioSpecificConfig
- HE-AAC v1: SBR noise floor / invf mode from within-band tonality
- HE-AAC v1: Move numEnvelopes/eff_amp_res/tEnv to SBRChannel for independent borders
- HE-AAC v1: Use dedicated noise Huffman tables in write_sbr_noise
