Fix regen: use properly-typed hidden Number/Textbox inputs for seg_idx and state_json

Previously seg_idx and state_json used taro_seed (gr.Number) as placeholder
for both — Gradio rejected a JSON string passed to a Number-type component,
causing process_completed success=false immediately. Now each tab has dedicated
hidden gr.Number (regen_seg) and gr.Textbox (regen_state) components with
matching elem_ids, so queue/join type validation passes.

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

app.py

@@ -1760,8 +1760,11 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     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")
                     taro_cf_db   = gr.Textbox(label="Crossfade Boost (dB)", value="3", elem_id="taro_cf_db")
-                    taro_samples = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
-                    taro_btn     = gr.Button("Generate", variant="primary")
+                    taro_samples    = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
+                    taro_btn        = gr.Button("Generate", variant="primary")
+                    # Hidden regen plumbing — do NOT remove (used as typed inputs for regen handlers)
+                    taro_regen_seg  = gr.Number(value=0, visible=False, elem_id="taro_regen_seg")
+                    taro_regen_state = gr.Textbox(value="", visible=False, elem_id="taro_regen_state")
 
                 with gr.Column():
                     (taro_slot_grps, taro_slot_vids,
@@ -1842,7 +1845,7 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     return _do
                 _btn.click(
                     fn=_make_taro_regen(_i, _slot_id),
-                    inputs=[taro_seed, taro_seed,   # seg_idx, state_json placeholders
+                    inputs=[taro_regen_seg, taro_regen_state,
                             taro_video, taro_seed, taro_cfg, taro_steps,
                             taro_mode, taro_cf_dur, taro_cf_db],
                     outputs=[taro_slot_vids[_i], taro_slot_waves[_i]],
@@ -1863,8 +1866,11 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     mma_steps    = gr.Slider(label="Steps", minimum=10, maximum=50, value=25, step=1, elem_id="mma_steps")
                     mma_cf_dur   = gr.Slider(label="Crossfade Duration (s)", minimum=0, maximum=8, value=2, step=0.1, elem_id="mma_cf_dur")
                     mma_cf_db    = gr.Textbox(label="Crossfade Boost (dB)", value="3", elem_id="mma_cf_db")
-                    mma_samples  = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
-                    mma_btn      = gr.Button("Generate", variant="primary")
+                    mma_samples     = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
+                    mma_btn         = gr.Button("Generate", variant="primary")
+                    # Hidden regen plumbing
+                    mma_regen_seg   = gr.Number(value=0, visible=False, elem_id="mma_regen_seg")
+                    mma_regen_state = gr.Textbox(value="", visible=False, elem_id="mma_regen_state")
 
                 with gr.Column():
                     (mma_slot_grps, mma_slot_vids,
@@ -1928,7 +1934,7 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     return _do
                 _btn.click(
                     fn=_make_mma_regen(_i, _slot_id),
-                    inputs=[mma_seed, mma_seed,   # seg_idx, state_json placeholders
+                    inputs=[mma_regen_seg, mma_regen_state,
                             mma_video, mma_prompt, mma_neg, mma_seed,
                             mma_cfg, mma_steps, mma_cf_dur, mma_cf_db],
                     outputs=[mma_slot_vids[_i], mma_slot_waves[_i]],
@@ -1950,8 +1956,11 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     hf_size     = gr.Radio(label="Model Size", choices=["xl", "xxl"], value="xxl", elem_id="hf_size")
                     hf_cf_dur   = gr.Slider(label="Crossfade Duration (s)", minimum=0, maximum=8, value=2, step=0.1, elem_id="hf_cf_dur")
                     hf_cf_db    = gr.Textbox(label="Crossfade Boost (dB)", value="3", elem_id="hf_cf_db")
-                    hf_samples  = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
-                    hf_btn      = gr.Button("Generate", variant="primary")
+                    hf_samples      = gr.Slider(label="Generations", minimum=1, maximum=MAX_SLOTS, value=1, step=1)
+                    hf_btn          = gr.Button("Generate", variant="primary")
+                    # Hidden regen plumbing
+                    hf_regen_seg    = gr.Number(value=0, visible=False, elem_id="hf_regen_seg")
+                    hf_regen_state  = gr.Textbox(value="", visible=False, elem_id="hf_regen_state")
 
                 with gr.Column():
                     (hf_slot_grps, hf_slot_vids,
@@ -2015,7 +2024,7 @@ with gr.Blocks(title="Generate Audio for Video", css=_SLOT_CSS, js=_GLOBAL_JS) a
                     return _do
                 _btn.click(
                     fn=_make_hf_regen(_i, _slot_id),
-                    inputs=[hf_seed, hf_seed,   # seg_idx, state_json placeholders
+                    inputs=[hf_regen_seg, hf_regen_state,
                             hf_video, hf_prompt, hf_neg, hf_seed,
                             hf_guidance, hf_steps, hf_size, hf_cf_dur, hf_cf_db],
                     outputs=[hf_slot_vids[_i], hf_slot_waves[_i]],