Improve TypeScript types and error handling

- Created proper TypeScript types for Office API operations
- Replaced 'any' casts with appropriate types
- Added type-safe utility functions in office-types.ts
- Improved error handling with proper unknown type
- Added helper functions for PowerPoint shape operations
- Created proper TypeScript interface for webpack HMR

These changes improve code quality, maintainability, and help catch potential bugs at compile time rather than runtime.

🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

src/taskpane/index.tsx

@@ -19,9 +19,21 @@ Office.onReady(() => {
   );
 });
 
-if ((module as any).hot) {
-  (module as any).hot.accept("./components/App", () => {
+// Define proper module hot interface for webpack hot module replacement
+interface HotModule extends NodeModule {
+  hot?: {
+    accept(path: string, callback: () => void): void;
+  };
+}
+
+// Use the proper type for module with HMR
+if ((module as HotModule).hot) {
+  (module as HotModule).hot?.accept("./components/App", () => {
     const NextApp = require("./components/App").default;
-    root?.render(NextApp);
+    root?.render(
+      <FluentProvider theme={webLightTheme}>
+        <NextApp title={title} />
+      </FluentProvider>
+    );
   });
 }