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

.forgejo/workflows/release.yml

@@ -56,7 +56,7 @@ jobs:
     steps:
       - name: Install dependencies and checkout
         run: |
-          apt-get update && apt-get install -y --no-install-recommends bash git python3
+          apt-get update && apt-get install -y --no-install-recommends bash git python3 ca-certificates
           git clone ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git .
           git checkout ${GITHUB_SHA}