v1.16.0 — Dashboard UI improvements & ESLint

Changes

• Wider layout — Content area expanded from 1024px to 1280px in both dev-dashboard and dev-board, reducing empty gutters on wide screens
• 3-column grid — Board overview uses 3 columns on xl screens
• Larger fonts — Base font size bumped to 18px across both views, pixel-based sizes scaled proportionally
• Clearer rail selection — Selected items now use a white left border + blue tint background instead of the barely-visible dark shade
• Removed notifications — Stripped the unused notification bell button and its hook
• WebSocket dev proxy fix — Client now connects to /ws path so Vite properly proxies to the backend in dev mode
• ESLint + Prettier — Added typescript-eslint and Prettier for the dashboard, integrated into pre-commit hook
• Code cleanup — Fixed unused imports/vars, removed dead useNotifications.ts, formatted all source files