Normalize Linux audio pipeline to lossless Float32 (skill: lossless-audio-compliance)

- native bridge WAV writers: 16-bit PCM truncation -> IEEE Float32 (fmt 3, bit-exact)
- vendor sheredom_json.h (vst3sdk 3.8.1 lacks moduleinfo/json.h)
- Dockerfile: drop nonexistent sfizz tag v1.2.3
- Python sf.write -> subtype=FLOAT everywhere
- resample_poly -> kaiser(16) window (>=130dB stopband)
- audio_editor._write_wav_lossless(): FLOAT passthrough, TPDF dither only for
  8/16/24-bit final exports
- app.jsx WAV encoders: Float32 default, TPDF dither for integer depths, fix 24-bit
- tests: lossless compliance gate (null test < -140dBFS, float32 format) 9/9 pass
- TASKS_WINDOWS_AUDIO_NORMALIZE.md: Windows-side remaining tasks

app/core/render_engine.py

@@ -146,6 +146,7 @@ class PythonRenderEngine:
                                     up=self.sample_rate // g,
                                     down=sr // g,
                                     axis=-1,
+                                    window=("kaiser", 16),  # stopband >= 130 dB (lossless-audio-compliance)
                                 )
                                 sr = self.sample_rate
                             
@@ -499,5 +500,5 @@ class PythonRenderEngine:
                 master_buffer /= max_peak
 
             # Write final output file
-            sf.write(output_filepath, master_buffer.T, self.sample_rate)
+            sf.write(output_filepath, master_buffer.T, self.sample_rate, subtype="FLOAT")
             return output_filepath