feat: add "Choose from Server" attachment picker to claim/preauth forms and chatbot

Native file inputs can't be pointed at a default server folder for security
reasons, so instead the Browse buttons on the Claim/PreAuth/Select Procedures
forms and the AI chatbot's attach button now also offer picking from
previously saved Cloud Storage attachments (e.g. Copy Agent screenshots) via
a new server-side picker modal, scoped per-patient on the claim forms and
unscoped (recent across all patients) in the chatbot.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/Backend/src/routes/claims.ts

@@ -158,6 +158,49 @@ router.post(
   }
 );
 
+// GET /api/claims/patient-attachments?patientId=123
+// Lists this patient's previously saved Cloud Storage "Attachments" (e.g. Copy Agent screenshots)
+// so they can be picked and re-attached to a claim/preauth without re-uploading from disk.
+router.get(
+  "/patient-attachments",
+  async (req: Request, res: Response): Promise<any> => {
+    if (!req.user?.id) return res.status(401).json({ error: "Unauthorized" });
+
+    const patientId = Number(req.query.patientId);
+    if (!patientId || isNaN(patientId)) {
+      return res.status(400).json({ error: "Invalid patientId" });
+    }
+
+    try {
+      const files = await storage.listPatientCategoryCloudFiles(patientId, "Attachments");
+      return res.json({ error: false, data: files });
+    } catch (err: any) {
+      console.error("[patient-attachments]", err);
+      return res.status(500).json({ error: "Failed to list attachments", message: err?.message });
+    }
+  }
+);
+
+// GET /api/claims/recent-attachments?limit=20
+// Lists recently saved Cloud Storage "Attachments" across all patients (e.g. Copy Agent
+// screenshots), for use in contexts (like the AI chatbot) that don't have a patient in scope yet.
+router.get(
+  "/recent-attachments",
+  async (req: Request, res: Response): Promise<any> => {
+    if (!req.user?.id) return res.status(401).json({ error: "Unauthorized" });
+
+    const limit = Number(req.query.limit) || 20;
+
+    try {
+      const files = await storage.listRecentAttachmentFiles(limit);
+      return res.json({ error: false, data: files });
+    } catch (err: any) {
+      console.error("[recent-attachments]", err);
+      return res.status(500).json({ error: "Failed to list attachments", message: err?.message });
+    }
+  }
+);
+
 router.post(
   "/mh-provider-login",
   async (req: Request, res: Response): Promise<any> => {