feat: dim frame thumbnail when its switch is toggled off

Thumbnail opacity is 1.0 when the frame switch is on, 0.25 when off.
Initial state reflects the current logic index bit, and updates live
on toggle without requiring a page refresh.

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

tab_batch_ng.py

@@ -566,9 +566,11 @@ def _render_sequence_card(i, seq, batch_list, data, file_path, state,
                     (2, 'End Frame', 'end frame path', 'end frame high strength', 'end frame low strength'),
                 ]:
                     ui.label(img_label).classes('text-caption text-weight-bold q-mt-sm')
+                    is_on = bool((logic_val >> bit) & 1)
                     with ui.row().classes('w-full items-center no-wrap q-mt-xs'):
                         inp = dict_input(ui.input, 'Path', seq, img_key).classes(
                             'col').props('outlined dense input-style="text-align: right"')
+                        thumb = None
                         img_path = Path(seq.get(img_key, '')) if seq.get(img_key) else None
                         if (img_path and img_path.exists() and
                                 img_path.suffix.lower() in IMAGE_EXTENSIONS):
@@ -576,13 +578,17 @@ def _render_sequence_card(i, seq, batch_list, data, file_path, state,
                             with ui.dialog() as img_dlg, ui.card().style('max-width:90vw; padding:0'):
                                 ui.html(f'<img src="{img_url}" '
                                         f'style="max-width:80vw;max-height:80vh;display:block">')
-                            ui.html(
+                            thumb = ui.html(
                                 f'<img src="{img_url}" '
                                 f'style="width:36px;height:36px;object-fit:cover;'
-                                f'border-radius:4px;cursor:pointer;flex-shrink:0">'
+                                f'border-radius:4px;cursor:pointer;flex-shrink:0;'
+                                f'opacity:{"1.0" if is_on else "0.25"}">'
                             ).on('click', img_dlg.open)
-                        sw = ui.switch(value=bool((logic_val >> bit) & 1))
+                        sw = ui.switch(value=is_on)
                         frame_switches.append(sw)
+                        if thumb is not None:
+                            sw.on('update:model-value',
+                                  lambda e, t=thumb: t.style(f'opacity: {"1.0" if e.args else "0.25"}'))
                     with ui.row().classes('w-full no-wrap q-mt-xs q-gutter-xs'):
                         dict_number('High', seq, hi_key, default=1.0,
                                     step=0.05, format='%.2f').classes('col').props('outlined dense')