Make picture frame properties relative and fix picture aspect ratio

Frame thickness, corner radius, padding, inner depth and picture depth
are now normalized factors (scale with Size, no dead clamp zones).
Picture aspect is computed inside-out so padding and frame thickness
no longer distort the image. New Frame Inner.mat as inner default.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Scripts/Components/PictureFrameBuilder.cs.meta

@@ -5,9 +5,10 @@ MonoImporter:
   serializedVersion: 2
   defaultReferences:
   - _pictureMaterial: {instanceID: 0}
-  - _innerMaterial: {fileID: 2100000, guid: a7794896ef878a64399cca929db5c43c, type: 2}
+  - _innerMaterial: {fileID: 2100000, guid: bc0ac45503ad5c44b8b966da0d0a40d3, type: 2}
   - _frameMaterial: {fileID: 2100000, guid: a7794896ef878a64399cca929db5c43c, type: 2}
   - _backMaterial: {fileID: 2100000, guid: a7794896ef878a64399cca929db5c43c, type: 2}
+  - _colliderRoot: {instanceID: 0}
   executionOrder: 0
   icon: {instanceID: 0}
   userData: