Add EntitySelect/IconSelect UI improvements across modals

- Portal IconSelect popups to document.body with position:fixed to prevent
  clipping by modal overflow-y:auto
- Replace custom scene selectors in automation editor with EntitySelect
  command-palette pickers (main scene + fallback scene)
- Add IconSelect grid for automation deactivation mode (none/revert/fallback)
- Add IconSelect grid for automation condition type and match type
- Replace mapped zone source dropdowns with EntitySelect pickers
- Replace scene target selector with EntityPalette.pick() pattern
- Remove effect palette preview bar from CSS editor
- Remove sensitivity badge from audio color strip source cards
- Clean up unused scene-selector CSS and scene-target-add-row CSS
- Add locale keys for all new UI elements across en/ru/zh

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

CLAUDE.md

@@ -120,6 +120,16 @@ Add hint text to both `en.json` and `ru.json` locale files using a `.hint` suffi
 
 Do **not** add placeholder options like `-- Select something --`. Populate the `<select>` with real options only and let the first one be selected by default.
 
+### Enhanced selectors (IconSelect & EntitySelect)
+
+Plain `<select>` dropdowns should be enhanced with visual selectors depending on the data type:
+
+- **Predefined options** (source types, effect types, palettes, waveforms, viz modes) → use `IconSelect` from `js/core/icon-select.js`. This replaces the `<select>` with a visual grid of icon+label+description cells. See `_ensureCSSTypeIconSelect()`, `_ensureEffectTypeIconSelect()`, `_ensureInterpolationIconSelect()` in `color-strips.js` for examples.
+
+- **Entity references** (picture sources, audio sources, devices, templates, clocks) → use `EntitySelect` from `js/core/entity-palette.js`. This replaces the `<select>` with a searchable command-palette-style picker. See `_cssPictureSourceEntitySelect` in `color-strips.js` or `_lineSourceEntitySelect` in `advanced-calibration.js` for examples.
+
+Both widgets hide the native `<select>` but keep it in the DOM with its value in sync. After programmatically changing the `<select>` value, call `.refresh()` (EntitySelect) or `.setValue(val)` (IconSelect) to update the trigger display. Call `.destroy()` when the modal closes.
+
 ### Modal dirty check (discard unsaved changes)
 
 Every editor modal **must** have a dirty check so closing with unsaved changes shows a "Discard unsaved changes?" confirmation. Use the `Modal` base class pattern from `js/core/modal.js`: