Tree Cleanup tool: bulk fixes with preview → approve

A new per-tree Cleanup page (and cleanup_service + endpoints), each fix
preview-first per the propose-then-approve rule:

- Mark deceased by birth year: lists people born ≤ a cutoff (default 1930) not
  already deceased; apply sets is_living=false for the ones you keep checked.
- Set sex from a source GEDCOM: upload the source .ged (it carries SEX); matches
  by name and proposes sex only where it's missing — far more accurate than
  guessing from first names. Review, then apply.
- Names that look broken: flags date-in-surname / date-in-given / no-surname /
  packed given names, with inline editable given+surname; fix the checked ones.

No migration (uses existing columns). 55 backend tests pass (preview+apply for
all three); frontend builds.

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

backend/app/schemas/cleanup.py

@@ -0,0 +1,50 @@
+import uuid
+
+from pydantic import BaseModel
+
+
+class DeceasedCandidate(BaseModel):
+    person_id: uuid.UUID
+    name: str
+    birth_year: int
+
+
+class DeceasedApply(BaseModel):
+    person_ids: list[uuid.UUID]
+
+
+class GenderProposal(BaseModel):
+    person_id: uuid.UUID
+    name: str
+    proposed_gender: str
+
+
+class GenderUpdate(BaseModel):
+    person_id: uuid.UUID
+    gender: str
+
+
+class GenderApply(BaseModel):
+    updates: list[GenderUpdate]
+
+
+class NameIssue(BaseModel):
+    name_id: uuid.UUID
+    person_id: uuid.UUID
+    given: str | None = None
+    surname: str | None = None
+    issue: str
+
+
+class NameEdit(BaseModel):
+    name_id: uuid.UUID
+    given: str | None = None
+    surname: str | None = None
+
+
+class NameApply(BaseModel):
+    edits: list[NameEdit]
+
+
+class CleanupResult(BaseModel):
+    updated: int