feat: add PDF export for analysis reports

Add a new /export/{company_name}/pdf endpoint that generates a formatted
PDF report using reportlab, including a summary table and all analysis
results. Add the corresponding frontend Export PDF button alongside the
existing Export CSV button on the Analysis page.

Closes leeworks-agents/SPARC#85

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/client.ts

@@ -141,6 +141,21 @@ export const exportApi = {
     link.remove();
     window.URL.revokeObjectURL(url);
   },
+  exportPdf: async (companyName: string): Promise<void> => {
+    const response = await api.get(`/export/${encodeURIComponent(companyName)}/pdf`, {
+      responseType: 'blob',
+    });
+    const safeName = companyName.toLowerCase().replace(/\s+/g, '_');
+    const date = new Date().toISOString().split('T')[0];
+    const url = window.URL.createObjectURL(new Blob([response.data], { type: 'application/pdf' }));
+    const link = document.createElement('a');
+    link.href = url;
+    link.setAttribute('download', `${safeName}-analysis-${date}.pdf`);
+    document.body.appendChild(link);
+    link.click();
+    link.remove();
+    window.URL.revokeObjectURL(url);
+  },
 };
 
 // Analytics API