v0.2.1: top-bar avatar, You/Admin settings groups, admin models

- Replace the gear/username button with a round initials avatar (per-user
  deterministic color via a new daybook_extras template filter); dropdown
  now shows the username and keeps Settings/About/theme/logout. Sets up an
  optional profile photo later.
- Regroup the settings nav into "You" (Account, API Keys, Storage, Demo
  Data) and a superuser-only "Admin" (Users), About separate — the split
  now reflects who each setting affects, not a flat list.
- Register ApiKey (key read-only) and TagColor in Django admin so /admin/
  is complete as the operator break-glass tool, distinct from the themed
  Settings product surface.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -8,6 +8,19 @@ the git tags (`vX.Y.Z`) and `daybook_project.__version__`.
 
 _Nothing yet._
 
+## [0.2.1] — 2026-09-04
+
+### Added
+- Top-bar **avatar**: a round initials badge (deterministic per-user color)
+  replaces the gear/username button; lays the groundwork for profile photos.
+- Django admin now registers `ApiKey` and `TagColor`, so `/admin/` is complete
+  as an operator break-glass tool (key value shown read-only).
+
+### Changed
+- Settings nav regrouped into **You** (Account, API Keys, Storage, Demo Data)
+  and a superuser-only **Admin** (Users) section, with About on its own — the
+  personal/admin split now mirrors who each setting affects.
+
 ## [0.2.0] — 2026-09-04
 
 ### Added
@@ -85,7 +98,8 @@ First tagged release.
 - Dockerised (Gunicorn + whitenoise), SQLite, `git`-based deploy with a
   runbook (`deploy/cloud_agent_deploy.md`) and health check.
 
-[Unreleased]: https://git.cygnus.systems/peter/daybook/compare/v0.2.0...HEAD
+[Unreleased]: https://git.cygnus.systems/peter/daybook/compare/v0.2.1...HEAD
+[0.2.1]: https://git.cygnus.systems/peter/daybook/compare/v0.2.0...v0.2.1
 [0.2.0]: https://git.cygnus.systems/peter/daybook/compare/v0.1.1...v0.2.0
 [0.1.1]: https://git.cygnus.systems/peter/daybook/compare/v0.1.0...v0.1.1
 [0.1.0]: https://git.cygnus.systems/peter/daybook/releases/tag/v0.1.0