feat(ui): keyboard shortcuts, perf monitor, toast system, theme toggle, WCAG a11y

[natiixnt]

Summary

• Keyboard shortcuts system - press ? for overlay with all shortcuts (1-8 tab switching, T theme, P perf monitor)
• Performance monitor - real-time FPS, memory, latency with sparkline charts, draggable panel
• Toast notification system - 4 types (success/error/warning/info), stacking, auto-dismiss with progress bar, pause on hover
• Dark/light theme toggle - button in header, localStorage persistence, respects system preference
• WCAG accessibility - skip-to-content link, ARIA roles/attributes on all tabs and panels, arrow key navigation, focus-visible outlines
• ESLint config for UI directory with security and quality rules

Test plan

• Open ui/index.html in browser, verify page loads without console errors
• Press ? to open keyboard shortcuts overlay, press Esc to close
• Press 1-8 to switch tabs, verify correct tab activates
• Press P to toggle performance monitor, verify FPS/memory display
• Press T to toggle dark/light theme, verify persistence across reload
• Tab through navigation with keyboard, verify focus rings and arrow key navigation
• Verify toast notifications appear on backend status changes
• Run screen reader (VoiceOver) to verify ARIA landmarks and labels

[ruvnet]

Hi @natiixnt — the 5-PR UI stack (#305 → #306 → #307 → #308 → #309) all touch the same shared files (ui/.eslintrc.json, ui/app.js, ui/components/TabManager.js) plus PR-specific additions. Two requests:

1. Pick a merge strategy. Either (a) squash all 5 into one comprehensive 'UI overhaul' PR with a single test plan, or (b) keep them stacked but rebase feat(ui): keyboard shortcuts, perf monitor, toast system, theme toggle, WCAG a11y #305 against current main first so the stack base is clean — then feat(ui): command palette, activity log, data export, fullscreen, connection status #306 against feat(ui): keyboard shortcuts, perf monitor, toast system, theme toggle, WCAG a11y #305, etc. Today they all fork from older main and will pairwise-conflict.

2. Confirm the .claude-flow/agents/ changes are intentional.* I see those listed in the diffs — ui/ is the right scope, but agent-definition files under .claude-flow/agents/ and .claude/agents/ shouldn't be touched by UI feature work unless that's part of the scope.

The feature set is great — keyboard shortcuts, perf monitor, toasts, theme toggle, command palette, activity log, mobile PWA, URL routing, onboarding, i18n, accessibility — all directly useful. Once the rebase / squash is sorted I'll do a focused review on whichever shape you ship. Same comment going on #306–#309.

[natiixnt]

Consolidating into #620 per maintainer's request in the discussion above. The new PR is a fresh single branch off current main with all five feature sets (keyboard shortcuts/perf/toasts/theme/a11y, command palette/activity log/export/fullscreen/connection status, mobile/PWA/tests, routing/onboarding/idle/notifications, i18n/screenshot/settings/uptime). The .claude-flow/agents/* and .claude/agents/* out-of-scope edits are dropped. Test plan in #620 covers all features in one pass.