ui: brand-consistent button and card styling

Replace traffic light colors (green/yellow/red) with brand palette:
- Primary actions: blue gradient
- Secondary actions: ghost/outline
- Destructive actions: ghost with red hover (modals keep filled red)
- Running cards: blue glow instead of green border
- Bottom-aligned buttons via flexbox column layout

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,14 @@
 ## Changelog
 
+### v0.31.6 — UI: Brand-consistent button & card styling (2026-02-25)
+
+#### Changed
+- **Buttons**: Replaced traffic light colors (green/yellow/red) with brand-consistent palette — primary actions use blue gradient, secondary actions use ghost/outline, destructive actions show red tint on hover only (modal confirmations keep filled red)
+- **Card borders**: Running apps now show a subtle blue glow instead of green top border; all other states have neutral borders
+- **Status badges**: Running state badge uses brand blue instead of green
+- **Button alignment**: Cards use flexbox column layout with `margin-top: auto` on actions — buttons always align to the bottom regardless of card content height
+- **Dashboard cards**: Left border indicator changed from green to blue for running apps
+
 ### v0.31.5 — Fix Nextcloud-OnlyOffice callback URL + trusted_domains (2026-02-25)
 
 #### Fixed