fix: use valid CSS color space names in toValue()

colorjs uses internal short names (p3, a98rgb, prophoto) that don't
match the CSS predefined color space identifiers required by the spec:
  - p3      → display-p3
  - a98rgb  → a98-rgb
  - prophoto → prophoto-rgb

This caused toValue() to emit invalid CSS like `color(p3 ...)`, which
the css-tree lexer rejects when re-validating the value in the CSS value
input (e.g. after a round-trip through the style panel).

Author: kof

packages/css-engine/src/core/to-value.test.ts

@@ -446,7 +446,6 @@ describe("Convert WS CSS Values to native CSS strings", () => {
         expect(value).toBe(expected);
       });
     }
-  });
 
   test("color in tuple", () => {
     const value = toValue({

packages/css-engine/src/core/to-value.ts

@@ -122,7 +122,7 @@ export const toValue = (
       case "oklch":
         return `oklch(${c1} ${c2} ${c3} / ${alpha})`;
       // Fall back to color() function for less common color spaces.
-      // colorjs uses internal short names that differ from CSS predefined color space identifiers.
+      // Webstudio uses colorjs internal names; map to CSS predefined color space names.
       case "p3":
         return `color(display-p3 ${c1} ${c2} ${c3} / ${alpha})`;
       case "a98rgb":