Adds a "People with no sex set" section to the Cleanup page — lists everyone
whose gender is still null with inline ♂ Male / ♀ Female buttons (and a link to
their page). Refreshes after the source-match and first-name guess passes, so
it's the manual mop-up for whatever those leave behind.
Frontend only (reuses person list + PATCH) — no migration.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
justin
a53858f920