Refine appearance settings and syntax highlighting

Keep parsed chat and tool detail content in sync with appearance token changes. Hide font-family controls on native, use One as the default syntax theme, add Swift highlighting, and give Nord a distinct light palette.

packages/highlight/src/__tests__/parsers.test.ts

@@ -13,6 +13,7 @@ describe("isLanguageSupported", () => {
     expect(isLanguageSupported("test.css")).toBe(true);
     expect(isLanguageSupported("test.html")).toBe(true);
     expect(isLanguageSupported("test.java")).toBe(true);
+    expect(isLanguageSupported("test.swift")).toBe(true);
     expect(isLanguageSupported("test.ex")).toBe(true);
   });
 
@@ -49,6 +50,7 @@ describe("getSupportedExtensions", () => {
     expect(extensions).toContain("py");
     expect(extensions).toContain("go");
     expect(extensions).toContain("rs");
+    expect(extensions).toContain("swift");
     expect(extensions).toContain("json");
   });
 });