fix(email): gate draft attempt rotation

Rotate persisted delivery identity only after the matching owner attempt is definitively failed. Keep stale, foreign, pending, sent, and uncertain drafts non-retryable.

job-tracker-ui/src/views/CorrespondenceInboxPage.tsx

@@ -388,8 +388,23 @@ export default function CorrespondenceInboxPage() {
     }
   };
 
-  const prepareNewAttempt = () => {
-    setDraft((current) => current ? { ...current, clientRequestId: globalThis.crypto.randomUUID() } : null);
+  const prepareNewAttempt = async () => {
+    if (!draft || sendResult?.status !== "failed") return;
+    setDraftError(null);
+    if (draft.id && draft.revision) {
+      try {
+        const response = await api.post<StoredEmailDraft>(`/email/drafts/${draft.id}/new-attempt`, { revision: draft.revision });
+        setDraft((current) => current ? { ...current, ...response.data } : null);
+        await loadStoredDrafts();
+      } catch (error: any) {
+        setDraftError(error?.response?.status === 409
+          ? "A new attempt is allowed only after the latest saved draft has a definitive failed delivery. Reload the draft before continuing."
+          : getApiErrorMessage(error, "Failed to prepare a new delivery attempt."));
+        return;
+      }
+    } else {
+      setDraft((current) => current ? { ...current, clientRequestId: globalThis.crypto.randomUUID() } : null);
+    }
     setSendResult(null);
     setSendError(null);
   };
@@ -524,7 +539,7 @@ export default function CorrespondenceInboxPage() {
             <Alert severity="warning" sx={{ mt: 1.5 }}>Delivery status is uncertain. Do not retry this draft. Check the provider Sent folder before taking any further action.</Alert>
           ) : null}
           {sendResult?.status === "failed" ? (
-            <Alert severity="error" sx={{ mt: 1.5 }} action={<Button color="inherit" size="small" onClick={prepareNewAttempt}>Prepare new attempt</Button>}>
+            <Alert severity="error" sx={{ mt: 1.5 }} action={<Button color="inherit" size="small" onClick={() => void prepareNewAttempt()}>Prepare new attempt</Button>}>
               The provider confirmed that this attempt did not complete. Review the connection and draft before creating a new attempt.
             </Alert>
           ) : null}