Separate guardians from members: a parent is not automatically a member

members/services/family.py enrolled a parent exactly like the child they were
registering, so every parent held a full membership: counted in the member
list, in the club and platform KPIs, and in the fee roll, with a fee record of
their own. ClubMembership.kind (member | guardian) separates the two.

A guardian is attached to the club only through their child. They hold the
login, can be contacted and can sit in a Group -- the stated exception -- but
they are not a member: no fee (clean() refuses one), absent from the member
list, the fee list and every member count, and not eligible for a roster or a
staff spot. A parent who also plays or coaches is a member who happens to be a
parent; the two facts are independent, which is why this is its own field
rather than inferred from FamilyMembership.role.

A field on ClubMembership rather than a separate model because everything that
answers "is this person attached to this club" already reads through that table
-- tenancy, groups, the club-wide event audience -- and a second kind of link
would need a parallel path through all of it. What changes is only who counts.

Two things that weren't obvious going in:

Excluding guardians had to be a subtraction, not a narrower filter. The obvious
move -- match only member-kind rows and drop the MEMBER-role branch, since an
active membership of any kind grants that role -- also hides someone the club
knows but hasn't signed up for a season yet, which is a real state the member
edit page supports. Two existing tests caught it. _guardians_only() subtracts
instead, so anyone who also plays, is on staff or runs the club stays visible.

Their tie to the club isn't seasonal but rides on a per-season row, so it has
to be carried forward or a parent silently drops off at the season boundary
while their child stays enrolled. Copied from the immediately preceding season
only, so a deliberate removal isn't resurrected from an older row.

The data migration reclassifies existing parents, deliberately skipping anyone
who plays, is on a team's staff or holds an elevated ClubRole -- demoting them
would strip them from their own team's roster eligibility. Anything ambiguous
stays a member, which an admin can flip; noticing someone quietly vanished is
much harder.

The import template gains a membership_kind column next to family_role (a
child marked guardian is refused), and the review screen shows what each row
will join as.

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

club/migrations/0022_clubmembership_kind.py

@@ -0,0 +1,23 @@
+# Generated by Django 6.0.6 on 2026-08-11 13:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('club', '0021_club_legal_name'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='clubmembership',
+            name='kind',
+            field=models.CharField(choices=[('member', 'member'), ('guardian', 'guardian')], default='member', help_text="A guardian is attached to the club only as a parent of a member -- they hold the login, but don't count as a member themselves and owe no fee. A parent who also plays is a member.", max_length=20, verbose_name='kind'),
+        ),
+        migrations.AlterField(
+            model_name='club',
+            name='legal_name',
+            field=models.CharField(blank=True, help_text='Full registered name (e.g. including a legal form like VZW/ASBL), used on official documents. Falls back to club name if blank.', max_length=255, verbose_name='legal name'),
+        ),
+    ]