feat: UI modernization — Manrope font, dark/light theme, card-based layouts

- Add Manrope as primary UI font via Google Fonts (wiregui/pages/style.py)
- Add dark/light/auto theme toggle in header, persisted to users.theme_preference
- Alembic migration for theme_preference column
- Redesign account page with card-based layout matching admin pages
- Convert settings page from tabs to stacked cards
- Replace all outline buttons with solid unelevated buttons
- Fix dark mode: remove hardcoded bg-grey-1/text-grey-7, use theme-safe colors
- Fix CI: add ca-certificates to release job for SSL cert verification
- Add no-coauthor and commit conventions to CLAUDE.md

CLAUDE.md

@@ -122,3 +122,7 @@ alembic/
 - Run with `uv run pytest`
 - Use `pytest-asyncio` for async tests
 - Test database: uses same Postgres instance, separate `wiregui_test` database
+
+## Git Commits
+- **Never** add `Co-Authored-By` lines or any AI attribution to commit messages
+- Follow conventional commits format (fix:, feat:, chore:, etc.) matching existing history