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/app/src/styles/markdown-styles.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { createMarkdownStyles } from "./markdown-styles";
+import { createCompactMarkdownStyles, createMarkdownStyles } from "./markdown-styles";
 import { darkTheme } from "./theme";
 
 describe("createMarkdownStyles", () => {
@@ -69,4 +69,28 @@ describe("createMarkdownStyles", () => {
       userSelect: "text",
     });
   });
+
+  it("uses the mono font-size token directly for inline and block code", () => {
+    const styles = createMarkdownStyles(darkTheme);
+    const compactStyles = createCompactMarkdownStyles(darkTheme);
+
+    expect(styles.code_inline).toMatchObject({
+      fontFamily: darkTheme.fontFamily.mono,
+      fontSize: darkTheme.fontSize.code,
+      lineHeight: Math.round(darkTheme.fontSize.code * 1.45),
+    });
+    expect(styles.code_block).toMatchObject({
+      fontFamily: darkTheme.fontFamily.mono,
+      fontSize: darkTheme.fontSize.code,
+    });
+    expect(styles.fence).toMatchObject({
+      fontFamily: darkTheme.fontFamily.mono,
+      fontSize: darkTheme.fontSize.code,
+    });
+    expect(compactStyles.code_inline).toMatchObject({
+      fontFamily: darkTheme.fontFamily.mono,
+      fontSize: darkTheme.fontSize.code,
+      lineHeight: Math.round(darkTheme.fontSize.code * 1.45),
+    });
+  });
 });

packages/app/src/styles/markdown-styles.ts

@@ -172,6 +172,7 @@ export function createMarkdownStyles(theme: Theme) {
       borderWidth: 0,
       fontFamily: theme.fontFamily.mono,
       fontSize: theme.fontSize.code,
+      lineHeight: Math.round(theme.fontSize.code * 1.45),
     },
 
     code_block: {
@@ -389,7 +390,7 @@ export function createCompactMarkdownStyles(theme: Theme) {
 
     code_inline: {
       ...baseStyles.code_inline,
-      fontSize: theme.fontSize.sm - 3,
+      fontSize: theme.fontSize.code,
     },
 
     code_block: {