chore: sanitize tooltips/comments + add experiment configs

- Replace all BJ references with generic "target style/audio" in
  activation steering, DITTO optimizer, and BigVGAN trainer
- Add latent_mixup_alpha/latent_noise_sigma to LoRA scheduler defaults
- Add bigvgan_disc_fm_retest.json and lora_optimized_dataset.json

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

nodes/selva_lora_scheduler.py

@@ -81,6 +81,8 @@ _PARAM_DEFAULTS = {
     "lr_schedule":         "constant",
     "init_mode":           "pissa",
     "use_rslora":          True,
+    "latent_mixup_alpha":  0.0,
+    "latent_noise_sigma":  0.0,
 }
 
 # Palette for comparison chart: one color per experiment (cycles if > 8)