fix: skip appointment-file merge for chatbot claims; add live screenshot capture to chatbot

- selenium-claim route no longer re-appends previously saved appointment
  attachments when the chatbot's autoSubmit flow already sent every intended
  file, preventing an unwanted extra upload (e.g. attach 2 -> Selenium sees 3).
- Add a "Take screenshot" button to the AI chatbot's attachment bar, reusing
  the same capture/crop flow as the appointment editor, so claims and
  preauths can be submitted from the chatbot with a live screenshot attached.

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

apps/Backend/src/routes/claims.ts

@@ -348,7 +348,9 @@ router.post(
 
       // Include attachments already saved on the appointment (e.g. via "Select Procedures")
       // that weren't re-uploaded in this request — read straight from disk by filePath.
-      if (claimData.appointmentId) {
+      // Skipped for chatbot-driven submissions, which already send every intended file and
+      // shouldn't have unrelated older appointment attachments silently tacked on.
+      if (claimData.appointmentId && !claimData.skipAppointmentAttachmentMerge) {
         const seenNames = new Set(filesForQueue.map((f) => f.originalname));
         const apptFiles = await storage.getAppointmentFiles(Number(claimData.appointmentId));
         for (const f of apptFiles) {