feat: add initial project setup with core PDF tools and utilities

- Implement core PDF manipulation tools (split, merge, convert, etc.)
- Add state management and UI utilities
- Set up build configuration with Vite and TailwindCSS
- Include essential dependencies for PDF processing
- Add gitignore and basic project configuration files

src/js/logic/flatten.ts

@@ -0,0 +1,27 @@
+import { showLoader, hideLoader, showAlert } from '../ui.js';
+import { downloadFile } from '../utils/helpers.js';
+import { state } from '../state.js';
+
+export async function flatten() {
+    if (!state.pdfDoc) {
+        showAlert('Error', 'PDF not loaded.');
+        return;
+    }
+    showLoader('Flattening PDF...');
+    try {
+        const form = state.pdfDoc.getForm();
+        form.flatten();
+
+        const flattenedBytes = await state.pdfDoc.save();
+        downloadFile(new Blob([flattenedBytes], { type: 'application/pdf' }), 'flattened.pdf');
+    } catch (e) {
+        console.error(e);
+        if (e.message.includes('getForm')) {
+            showAlert('No Form Found', 'This PDF does not contain any form fields to flatten.');
+        } else {
+            showAlert('Error', 'Could not flatten the PDF.');
+        }
+    } finally {
+        hideLoader();
+    }
+}