feat(admin): full legacy controller set in scene-inputs editor

The V2 scene-inputs editor only exposed ~15 of the content model's
~40 fields. Restore full parity with the legacy admin controller.

content-svc:
- SaveContentElementRequest + ContentElementResponse widened to the
  complete field set (text/font, direction/RTL, media, advanced, DP)
- ApplyElement / ToElementResponse map every field 1:1
  (Enum.TryParse for JustifyKind + AiInputType)

frontend (SceneInputsEditor):
- common fields up top; an "advanced" toggle reveals grouped sections:
  Text and Font, Direction (RTL/LTR), Media, Advanced, Design-Presets (DP)
- editing an element loads the full field set; rows show font/hidden badges
- nullable numbers sent as null, enums as named values (snake_case body)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/content/FlatRender.ContentSvc/Models/SceneColor.cs

@@ -52,17 +52,39 @@ public record SaveColorPresetRequest(
 // ── Scene content elements (the editable inputs inside a scene) ───────────────
 
 public record ContentElementResponse(
-    Guid Id, Guid SceneId, string Key, string Title, string? Hint,
+    Guid Id, Guid SceneId, string Key, string Title, string? LocalizedTitle, string? Hint,
     string Type, string? DefaultValue, int PositionInContainer,
-    bool IsTextBox, int? MaxSize, int? FontSize, bool IsFontChangeable,
-    bool IsFontSizeChangeable, bool VideoSupport, int? Width, int? Height,
-    string? Thumbnail
+    // text + font
+    bool IsTextBox, int? MaxSize, int? FontSize, int? DefaultFontSize,
+    string? FontFace, string? FontFaceName, string? DefaultFontFace,
+    bool IsFontChangeable, bool IsFontSizeChangeable, string Justify, bool CanJustify,
+    // direction / RTL
+    string? DirectionLayerKey, int DirectionLayerValue,
+    // media
+    bool VideoSupport, int? Width, int? Height, string? Thumbnail,
+    decimal? MinDurationSec, decimal? MaxDurationSec,
+    // advanced
+    string? MappedList, string? CounterMode, string AiInputType,
+    bool IsHidden, bool IsFocused, string? OpacityControllerKey, int VirtualCount,
+    // design-preset (dp) variants
+    string? Dp1Image, string? Dp1Title, string? Dp2Image, string? Dp2Title,
+    string? Dp3Image, string? Dp3Title, string? Dp4Image, string? Dp4Title
 );
 
 public record SaveContentElementRequest(
-    Guid SceneId, string Key, string Title, string? Hint,
-    string Type, string? DefaultValue, int PositionInContainer,
-    bool IsTextBox, int? MaxSize, int? FontSize,
-    bool IsFontChangeable, bool IsFontSizeChangeable,
-    bool VideoSupport, int? Width, int? Height, string? Thumbnail
+    Guid SceneId, string Key, string Title, string Type,
+    string? LocalizedTitle = null, string? Hint = null, string? DefaultValue = null,
+    int PositionInContainer = 0,
+    bool IsTextBox = false, int? MaxSize = null, int? FontSize = null, int? DefaultFontSize = null,
+    string? FontFace = null, string? FontFaceName = null, string? DefaultFontFace = null,
+    bool IsFontChangeable = false, bool IsFontSizeChangeable = false,
+    string? Justify = null, bool CanJustify = true,
+    string? DirectionLayerKey = null, int DirectionLayerValue = 0,
+    bool VideoSupport = false, int? Width = null, int? Height = null, string? Thumbnail = null,
+    decimal? MinDurationSec = null, decimal? MaxDurationSec = null,
+    string? MappedList = null, string? CounterMode = null, string? AiInputType = null,
+    bool IsHidden = false, bool IsFocused = false, string? OpacityControllerKey = null,
+    int VirtualCount = 1,
+    string? Dp1Image = null, string? Dp1Title = null, string? Dp2Image = null, string? Dp2Title = null,
+    string? Dp3Image = null, string? Dp3Title = null, string? Dp4Image = null, string? Dp4Title = null
 );