v0.12.0 — Instance administration on its own page (#149, #150)
- #149 Admin: `/admin` and `/admin/users/:id` behind a RequireAdmin guard,
moving administration out of Settings. Adds GET /api/v1/admin/overview and
GET /api/v1/admin/users/:id, and server-side search/filter/paging on
GET /api/v1/admin/users — whose response shape changed from `{ users }` to
`{ items, total }` (admin-only, off MCP, single in-image consumer).
The session resolver also began writing `sessions.last_used_at`, throttled.
- #150 Lists: a failed fetch no longer takes the loaded rows away, and offers
a retry; an empty state waits until the server has actually answered.
No schema change since v0.11.0 — migration 0022 is still the head.