fix: address codex review — 6 bug fixes for sponsor management

1. Add distinct=True to Count annotations in SponsorListView to prevent
   cross-multiplication of contacts × sponsorships
2. Benefit form checks bound POST year data so changing year + package
   in a single submit works
3. SponsorshipEditForm same fix for year-scoped package filtering
4. Clear package M2M on cloned benefits when clone_packages unchecked
5. Return sent_count from notification use case; show warning when
   zero emails were actually sent instead of false success
6. Show error when PDF generation fails but DOCX succeeds so staff
   know the contract was not finalized

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

Author: JacobCoffee

apps/sponsors/manage/views.py

@@ -1637,13 +1637,16 @@ def post(self, request, pk):
 
         if "confirm" in request.POST and form.is_valid():
             use_case = use_cases.SendSponsorshipNotificationUseCase.build()
-            use_case.execute(
+            sent = use_case.execute(
                 notification=form.get_notification(),
                 sponsorships=[sp],
                 contact_types=form.cleaned_data["contact_types"],
                 request=request,
             )
-            messages.success(request, f"Notification sent to {sp.sponsor.name} contacts.")
+            if sent:
+                messages.success(request, f"Notification sent to {sp.sponsor.name} contacts.")
+            else:
+                messages.warning(request, f"No matching contacts found for {sp.sponsor.name}. Nothing was sent.")
             return redirect(reverse("manage_sponsorship_detail", args=[pk]))
 
         context = {
@@ -2030,7 +2033,7 @@ def post(self, request):
 
         if "confirm" in request.POST and form.is_valid():
             use_case = use_cases.SendSponsorshipNotificationUseCase.build()
-            use_case.execute(
+            sent = use_case.execute(
                 notification=form.get_notification(),
                 sponsorships=sponsorships,
                 contact_types=form.cleaned_data["contact_types"],
@@ -2039,7 +2042,12 @@ def post(self, request):
             # Clear session data
             request.session.pop("bulk_notify_ids", None)
             names = ", ".join(sp.sponsor.name for sp in sponsorships if sp.sponsor)
-            messages.success(request, f"Notification sent to {len(sponsorships)} sponsor(s): {names}.")
+            if sent:
+                messages.success(request, f"Notification sent to {sent} of {len(sponsorships)} sponsor(s): {names}.")
+            else:
+                messages.warning(
+                    request, f"No matching contacts found for {len(sponsorships)} sponsor(s). Nothing was sent."
+                )
             return redirect(reverse("manage_sponsorships"))
 
         context = {
@@ -2857,9 +2865,11 @@ def _handle_send_proposal_with_contract(self, request, data, contract, sponsor):
             messages.error(request, "Failed to generate contract files. Check that pypandoc is installed.")
             return redirect(reverse("manage_composer") + "?step=6")
 
-        # Finalize the contract
+        # Finalize the contract — requires at least PDF to persist
         if pdf_bytes:
             contract.set_final_version(pdf_bytes, docx_bytes)
+        else:
+            messages.error(request, "PDF generation failed. Contract was not finalized. Only DOCX will be attached.")
 
         email = EmailMessage(
             subject=subject,

apps/sponsors/use_cases.py

@@ -193,12 +193,14 @@ def execute(self, notification: SponsorEmailNotificationTemplate, sponsorships,
             "to_manager": SponsorContact.MANAGER_CONTACT in contact_types,
         }
         request = kwargs.get("request")
+        sent_count = 0
 
         for sponsorship in sponsorships:
             email = notification.get_email_message(sponsorship, **msg_kwargs)
             if not email:
                 continue
             email.send()
+            sent_count += 1
 
             # Persist notification log (best-effort, don't break sending)
             try:
@@ -223,6 +225,8 @@ def execute(self, notification: SponsorEmailNotificationTemplate, sponsorships,
                 request=request,
             )
 
+        return sent_count
+
 
 class CloneSponsorshipYearUseCase(BaseUseCaseWithNotifications):
     """Clone sponsorship packages and benefits from one year to another."""