feat(resume): add PDF download functionality with server endpoint

- Add useResumePdf composable for client-side PDF download handling
- Implement /api/resume/pdf server endpoint for PDF generation
- Add puppeteer and @sparticuz/chromium dependencies for PDF rendering
- Add puppeteer-core for headless browser automation
- Update Vercel configuration to support PDF generation
- Include loading state management and error handling with toast notifications
- Implement blob download with automatic filename generation
- Add memory leak prevention through object URL revocation

app/composables/useResumePdf.ts

@@ -0,0 +1,51 @@
+/**
+ * PDF Download Composable
+ * Handles PDF download logic with loading state and error handling
+ */
+
+export function useResumePdf() {
+  const isGenerating = ref(false)
+  const toast = useToast()
+  const { getPdfFilename } = useResumeData()
+
+  async function downloadPdf() {
+    isGenerating.value = true
+
+    try {
+      // Fetch PDF as blob (AC1)
+      const response = await $fetch('/api/resume/pdf', {
+        responseType: 'blob',
+      })
+
+      // Create object URL from blob (AC2)
+      const url = URL.createObjectURL(response as Blob)
+
+      // Create temporary anchor element and trigger download
+      const a = document.createElement('a')
+      a.href = url
+      a.download = getPdfFilename() // AC3: filename from composable
+      a.click()
+
+      // Revoke object URL to prevent memory leaks (AC8)
+      URL.revokeObjectURL(url)
+    } catch (error) {
+      // Error handling (AC6)
+      console.error('PDF generation failed:', error)
+
+      toast.add({
+        title: 'Error generating PDF',
+        description: 'Please try again',
+        color: 'error',
+      })
+    } finally {
+      // Always reset loading state (AC7)
+      isGenerating.value = false
+    }
+  }
+
+  // Return composable interface (AC4, AC5)
+  return {
+    isGenerating,
+    downloadPdf,
+  }
+}