Alternate names (maiden/married), self-person link, deletion integrity

Names (the genealogy standard: maiden name primary, married/alias as typed
alternates):
- Name model already supported multiple typed names; expose full CRUD —
  NameCreate/Read/Update schemas, name_service (one-primary invariant,
  promote-on-delete), nested /persons/{id}/names routes.
- Person page gains a Names card: add/edit/delete + "make primary", with a
  curated name_type dropdown (birth/maiden, married, alias, nickname, …).

Self-person ("who am I"):
- users.self_person_id FK (use_alter for the users<->persons<->trees cycle)
  + migration; PATCH /users/me/self-person; "This is me" / "This is you"
  on the person page. Soft-deleting the linked person clears it.

Deletion integrity (fixes the broken tree view):
- delete_person now soft-deletes the relationships touching the person, so no
  dangling edges remain; family-chart also filters links to missing people.
- Optional cascade=true recursively deletes descendants (GEDCOM cleanup);
  the person page asks "only this person" vs "with all descendants".
- DELETE returns {deleted: n}.

Family view surfaces "Not connected to anyone" so dangling people aren't lost.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/services/person_service.py

@@ -6,11 +6,12 @@ person through the privacy engine. Each returned Person gets a transient
 import uuid
 from datetime import UTC, datetime
 
-from sqlalchemy import func, or_, select
+from sqlalchemy import func, or_, select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.models.enums import PersonPrivacy
+from app.models.enums import PersonPrivacy, RelationshipType
 from app.models.person import Name, Person
+from app.models.relationship import Relationship
 from app.models.tree import Tree
 from app.models.user import User
 from app.services import privacy
@@ -177,9 +178,65 @@ async def get_person(
     return person
 
 
-async def delete_person(
-    session: AsyncSession, *, actor: User, tree: Tree, person_id: uuid.UUID
+async def _children_of(
+    session: AsyncSession, *, tree_id: uuid.UUID, parent_id: uuid.UUID
+) -> list[uuid.UUID]:
+    rows = (
+        await session.execute(
+            select(Relationship.person_to_id).where(
+                Relationship.tree_id == tree_id,
+                Relationship.deleted_at.is_(None),
+                Relationship.type == RelationshipType.parent_child,
+                Relationship.person_from_id == parent_id,
+            )
+        )
+    ).scalars().all()
+    return list(rows)
+
+
+async def _soft_delete_one(
+    session: AsyncSession, *, actor: User, tree: Tree, person: Person, now: datetime
 ) -> None:
+    """Soft-delete a single person and the relationships touching them, so no
+    dangling edges are left to break the tree view."""
+    person.deleted_at = now
+    rels = (
+        await session.execute(
+            select(Relationship).where(
+                Relationship.tree_id == tree.id,
+                Relationship.deleted_at.is_(None),
+                or_(
+                    Relationship.person_from_id == person.id,
+                    Relationship.person_to_id == person.id,
+                ),
+            )
+        )
+    ).scalars().all()
+    for rel in rels:
+        rel.deleted_at = now
+    record_audit(
+        session,
+        action="delete",
+        entity_type="Person",
+        entity_id=person.id,
+        tree_id=tree.id,
+        actor_user_id=actor.id,
+        after={"cascaded_relationships": len(rels)},
+    )
+
+
+async def delete_person(
+    session: AsyncSession,
+    *,
+    actor: User,
+    tree: Tree,
+    person_id: uuid.UUID,
+    cascade: bool = False,
+) -> int:
+    """Soft-delete a person. Always removes the relationships that touch them
+    (preventing dangling edges). With ``cascade=True``, recursively deletes
+    their descendants too — handy for pruning a bad GEDCOM import. Returns the
+    number of persons deleted."""
     if not await privacy.can_edit_tree(session, user_id=actor.id, tree=tree):
         raise Forbidden("not an editor of this tree")
     person = (
@@ -191,16 +248,49 @@ async def delete_person(
     ).scalar_one_or_none()
     if person is None:
         raise NotFound("person not found")
-    person.deleted_at = datetime.now(UTC)
-    record_audit(
-        session,
-        action="delete",
-        entity_type="Person",
-        entity_id=person.id,
-        tree_id=tree.id,
-        actor_user_id=actor.id,
+
+    now = datetime.now(UTC)
+
+    # Gather the set of persons to delete. For cascade, walk descendants
+    # breadth-first, guarding against cycles.
+    to_delete: list[Person] = [person]
+    if cascade:
+        seen = {person.id}
+        frontier = [person.id]
+        while frontier:
+            nxt: list[uuid.UUID] = []
+            for pid in frontier:
+                for child_id in await _children_of(session, tree_id=tree.id, parent_id=pid):
+                    if child_id not in seen:
+                        seen.add(child_id)
+                        nxt.append(child_id)
+            frontier = nxt
+        extra_ids = [pid for pid in seen if pid != person.id]
+        if extra_ids:
+            extra = (
+                await session.execute(
+                    select(Person).where(
+                        Person.id.in_(extra_ids),
+                        Person.tree_id == tree.id,
+                        Person.deleted_at.is_(None),
+                    )
+                )
+            ).scalars().all()
+            to_delete.extend(extra)
+
+    for p in to_delete:
+        await _soft_delete_one(session, actor=actor, tree=tree, person=p, now=now)
+
+    # Soft delete leaves the row in place, so the DB-level "ON DELETE SET NULL"
+    # never fires — clear any account's self-person link to a deleted person.
+    await session.execute(
+        update(User)
+        .where(User.self_person_id.in_([p.id for p in to_delete]))
+        .values(self_person_id=None)
     )
+
     await session.commit()
+    return len(to_delete)
 
 
 async def restore_person(