Move JSDoc examples to type-checked .examples.ts files

Extract inline code examples from JSDoc comments into companion
`.examples.ts`/`.examples.tsx` files. Examples are now:

- Type-checked by wrapping them in functions
- Referenced via `{@includeCode ./file.examples.ts#regionName}` tags
- Organized using `//#region` and `//#endregion` markers

This keeps the main source files cleaner while ensuring examples
compile correctly. Updated TypeDoc config with `exampleTag: false`
to support title text on `@example` tags.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/react/useDocumentTheme.examples.tsx

@@ -0,0 +1,46 @@
+/**
+ * Type-checked examples for the useDocumentTheme hook.
+ *
+ * @module
+ */
+
+import { useDocumentTheme } from "./useDocumentTheme.js";
+
+// Stub components for examples
+declare function DarkIcon(): React.JSX.Element;
+declare function LightIcon(): React.JSX.Element;
+
+/**
+ * Example: Conditionally render based on theme.
+ */
+function useDocumentTheme_conditionalRender() {
+  //#region useDocumentTheme_conditionalRender
+  function MyApp() {
+    const theme = useDocumentTheme();
+
+    return <div>{theme === "dark" ? <DarkIcon /> : <LightIcon />}</div>;
+  }
+  //#endregion useDocumentTheme_conditionalRender
+}
+
+/**
+ * Example: Use with theme-aware styling.
+ */
+function useDocumentTheme_themedButton() {
+  //#region useDocumentTheme_themedButton
+  function ThemedButton() {
+    const theme = useDocumentTheme();
+
+    return (
+      <button
+        style={{
+          background: theme === "dark" ? "#333" : "#fff",
+          color: theme === "dark" ? "#fff" : "#333",
+        }}
+      >
+        Click me
+      </button>
+    );
+  }
+  //#endregion useDocumentTheme_themedButton
+}