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/schemas/name.py

@@ -0,0 +1,42 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict
+
+
+class NameCreate(BaseModel):
+    # Open vocabulary: birth/maiden, married, alias, religious, nickname, ...
+    name_type: str = "birth"
+    given: str | None = None
+    surname: str | None = None
+    prefix: str | None = None
+    suffix: str | None = None
+    nickname: str | None = None
+    is_primary: bool = False
+
+
+class NameUpdate(BaseModel):
+    name_type: str | None = None
+    given: str | None = None
+    surname: str | None = None
+    prefix: str | None = None
+    suffix: str | None = None
+    nickname: str | None = None
+    is_primary: bool | None = None
+
+
+class NameRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+
+    id: uuid.UUID
+    tree_id: uuid.UUID
+    person_id: uuid.UUID
+    name_type: str
+    given: str | None
+    surname: str | None
+    prefix: str | None
+    suffix: str | None
+    nickname: str | None
+    is_primary: bool
+    sort_order: int
+    created_at: datetime

backend/app/schemas/user.py

@@ -19,4 +19,10 @@ class UserRead(BaseModel):
     email: str
     display_name: str | None
     email_verified_at: datetime | None
+    self_person_id: uuid.UUID | None = None
     created_at: datetime
+
+
+class UserSelfPersonUpdate(BaseModel):
+    # null clears the link; otherwise the Person that represents this account.
+    self_person_id: uuid.UUID | None = None