Hybrid mode (SILK+CELT) at 48kHz produces broken output - only 32% energy

[rudra-kaal]

At 48kHz with VoIP or Audio mode, opus-rs uses Hybrid mode (SILK+CELT) which produces only ~32% energy instead of ~100%.

Evidence:

• Hybrid mode: 32% energy, SNR = -3dB (broken)
• SILK-only mode: 92% energy (works)
• Test: test_48k_hybrid_quality shows "CELT decoder output amplitude is ~35-40% of expected"

cargo test --test hybrid_48k_test
# Output: 48kHz Hybrid mode SNR: -3.00 dB
# WARNING: CELT decoder output amplitude is ~35-40% of expected

Expected: Hybrid mode should decode with similar quality to SILK-only (~90%+ energy)
Actual: Only ~32% energy - sounds like static/cracking

[shenjinti]

fixed in v0.1.18