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>

server/src/wled_controller/templates/modals/css-editor.html

@@ -22,6 +22,7 @@
                     <small class="input-hint" style="display:none" data-i18n="color_strip.type.hint">Picture Source derives colors from a screen capture. Static Color fills all LEDs with one constant color. Gradient distributes a color gradient across all LEDs.</small>
                     <select id="css-editor-type" onchange="onCSSTypeChange()">
                         <option value="picture" data-i18n="color_strip.type.picture">Picture Source</option>
+                        <option value="picture_advanced" data-i18n="color_strip.type.picture_advanced">Multi-Monitor</option>
                         <option value="static" data-i18n="color_strip.type.static">Static Color</option>
                         <option value="gradient" data-i18n="color_strip.type.gradient">Gradient</option>
                         <option value="color_cycle" data-i18n="color_strip.type.color_cycle">Color Cycle</option>
@@ -36,7 +37,7 @@
 
                 <!-- Picture-source-specific fields -->
                 <div id="css-editor-picture-section">
-                    <div class="form-group">
+                    <div id="css-editor-picture-source-group" class="form-group">
                         <div class="label-row">
                             <label for="css-editor-picture-source" data-i18n="color_strip.picture_source">Picture Source:</label>
                             <button type="button" class="hint-toggle" onclick="toggleHint(this)" title="?" data-i18n-aria-label="aria.hint">?</button>
@@ -211,7 +212,6 @@
                             <option value="aurora" data-i18n="color_strip.effect.aurora">Aurora</option>
                         </select>
                         <small id="css-editor-effect-type-desc" class="field-desc"></small>
-                        <div id="css-editor-effect-preview" class="effect-palette-preview"></div>
                     </div>
 
                     <div id="css-editor-effect-palette-group" class="form-group">
@@ -220,7 +220,7 @@
                             <button type="button" class="hint-toggle" onclick="toggleHint(this)" title="?" data-i18n-aria-label="aria.hint">?</button>
                         </div>
                         <small class="input-hint" style="display:none" data-i18n="color_strip.effect.palette.hint">Color palette used by the effect.</small>
-                        <select id="css-editor-effect-palette" onchange="updateEffectPreview()">
+                        <select id="css-editor-effect-palette">
                             <option value="fire" data-i18n="color_strip.palette.fire">Fire</option>
                             <option value="ocean" data-i18n="color_strip.palette.ocean">Ocean</option>
                             <option value="lava" data-i18n="color_strip.palette.lava">Lava</option>