Add a club legal address, used for invoices/referee forms ahead of the home ground

New Club.legal_address/legal_zip_code/legal_city, editable from the
identity page (management:club_settings). Official document headers
(the dues invoice, the referee payment form) previously borrowed the
club's home Location for this -- conflating "where we play" with "our
registered address", which aren't always the same place. New
club.services.invoicing.resolve_document_address(club) picks the club's
own legal address when set, falling back to the home Location exactly as
before when it isn't, so nothing breaks for a club that hasn't set one
yet. Location.is_home now means only what it always should have: telling
a home game from an away one.

Renamed the shared "home_location" template/context variable to
"document_address" on both PDFs to match -- it was never accurate once a
legal address could win instead.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9

club/models.py

@@ -50,6 +50,15 @@ class Club(UUIDModel):
     )
     website = models.URLField(_("website"), blank=True, help_text=_("The club's own site, if it has one -- shown alongside its RosterChief pages, not used for anything else yet."))
 
+    legal_address = models.CharField(
+        _("legal address"),
+        max_length=255,
+        blank=True,
+        help_text=_("Street address for official documents (invoices, the referee payment form). Falls back to the home location's address when left blank -- set this when the club's registered address isn't where it actually plays."),
+    )
+    legal_zip_code = models.CharField(_("legal zip code"), max_length=255, blank=True)
+    legal_city = models.CharField(_("legal city"), max_length=255, blank=True)
+
     logo = models.FileField(
         _("logo"),
         upload_to=club_logo_path,