fix: align defaults with official repos

- TARO CFG Scale: 7.5 → 8.0 (matches TARO/infer.py)
- MMAudio Negative Prompt: empty → "music" (matches MMAudio gradio_demo.py)

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

app.py

@@ -2350,7 +2350,7 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                 with gr.Column(scale=1):
                     taro_video   = gr.Video(label="Input Video")
                     taro_seed    = gr.Number(label="Seed (-1 = random)", value=-1, precision=0, elem_id="taro_seed")
-                    taro_cfg     = gr.Slider(label="CFG Scale", minimum=1, maximum=15, value=7.5, step=0.5, elem_id="taro_cfg")
+                    taro_cfg     = gr.Slider(label="CFG Scale", minimum=1, maximum=15, value=8.0, step=0.5, elem_id="taro_cfg")
                     taro_steps   = gr.Slider(label="Sampling Steps", minimum=10, maximum=50, value=25, step=1, elem_id="taro_steps")
                     taro_mode    = gr.Radio(label="Sampling Mode", choices=["sde", "ode"], value="sde", elem_id="taro_mode")
                     taro_cf_dur  = gr.Slider(label="Crossfade Duration (s)", minimum=0, maximum=8, value=2, step=0.1, elem_id="taro_cf_dur")
@@ -2415,7 +2415,7 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                 with gr.Column(scale=1):
                     mma_video    = gr.Video(label="Input Video")
                     mma_prompt   = gr.Textbox(label="Prompt", placeholder="e.g. footsteps on gravel", elem_id="mma_prompt")
-                    mma_neg      = gr.Textbox(label="Negative Prompt", placeholder="music, speech", elem_id="mma_neg")
+                    mma_neg      = gr.Textbox(label="Negative Prompt", value="music", placeholder="music, speech", elem_id="mma_neg")
                     mma_seed     = gr.Number(label="Seed (-1 = random)", value=-1, precision=0, elem_id="mma_seed")
                     mma_cfg      = gr.Slider(label="CFG Strength", minimum=1, maximum=10, value=4.5, step=0.5, elem_id="mma_cfg")
                     mma_steps    = gr.Slider(label="Steps", minimum=10, maximum=50, value=25, step=1, elem_id="mma_steps")