Fix the referee PDF's card background, make locations searchable, and add game end times to the API

Referee PDF: the info-card background used CSS color-mix(), which WeasyPrint
doesn't support -- the rule was silently dropped, leaving the card with no
background at all. Computed in Python instead (management/pdf.py) and baked
into the template as a plain hex value; the tint is based on the club's
primary_color, falling back to secondary_color when primary is itself (near)
black or white, where a straight tint would be invisible or too harsh.

Event forms: the location picker now shows "Name — City" (plus the country
when it isn't Belgium) and is searchable by name or city, reusing the
existing single-select searchable-select.js widget.

Games API: GameOut now carries `end` (explicit, or start + 2h when a GAME was
saved without one -- Event.save() sets this, never overwriting an explicit
end; other event kinds are untouched). /games/upcoming/ now includes
anything not yet finished rather than only things that haven't started, so a
game already in progress keeps showing up until its window closes; `status`
was adjusted to match so a game returned there never calls itself
"finished".

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

management/views.py

@@ -78,7 +78,7 @@ from .forms import (
     TeamMembershipForm,
     TeamPhotoForm,
 )
-from .pdf import PDFExportError, event_referee_form_pdf, membership_list_pdf
+from .pdf import PDFExportError, event_referee_form_pdf, membership_list_pdf, referee_form_colors
 from .recurrence_ui import describe_rrule
 
 
@@ -2143,7 +2143,7 @@ class EventRefereeFormPdfView(ClubAdminRequiredMixin, View):
         event = get_object_or_404(Event.objects.filter(club=request.club).prefetch_related("teams", "referees__member"), pk=pk)
         home_location = Location.objects.filter(club=request.club, is_home=True).first()
         referees = list(event.referees.all())
-        context = {"club": request.club, "event": event, "referees": referees, "home_location": home_location, "grand_total": sum((referee.total_payable for referee in referees), Decimal("0"))}
+        context = {"club": request.club, "event": event, "referees": referees, "home_location": home_location, "grand_total": sum((referee.total_payable for referee in referees), Decimal("0"))} | referee_form_colors(request.club)
 
         try:
             pdf = event_referee_form_pdf(context)