refactor(kanban): standardize column width and remove masonry layout

- Remove double-width styling from In Progress column
- Replace masonry 2-column layout with simple vertical stacking
- All Kanban columns now use uniform w-72 width
- Fix Settings view theme consistency with proper CSS variables
- Add action button color variables to theme system

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

.automaker/categories.json

@@ -2,5 +2,6 @@
   "Agent Runner",
   "Core",
   "Kanban",
-  "Other"
+  "Other",
+  "Settings"
 ]