feat: phase 8 — Vite/TS canvas-based KVM console frontend

crates/ericrfb-frontend — vanilla TypeScript + Vite:

login.ts:
- Login form POSTs to /api/login, receives applet_id
- Error display, auto-transitions to console view on success

console.ts:
- Canvas-based renderer sized to framebuffer dimensions
- WebSocket binary protocol decoder: TAG_BLIT → putImageData,
  TAG_RESIZE → canvas resize
- Keyboard capture: keydown/keyup → JS code → e-RIC scancode → WS
- Mouse capture: move/click/wheel → scaled coords + button mask → WS
- Right-click and context menu suppressed for pass-through

input.ts:
- Full 104-key JS KeyboardEvent.code → scancode mapping table

protocol.ts:
- Binary message builders matching proxy WS protocol tags

Toolbar: Ctrl+Alt+Del button, Fullscreen toggle.
Dark theme, pixelated canvas rendering, cursor hidden over console.

Vite config proxies /api to localhost:3000 for dev mode.
Build outputs to ../../dist for proxy static serving.

Builds to 5.8KB JS + 1.4KB CSS gzipped.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1 +1,4 @@
 /target
+/dist
+/out
+crates/ericrfb-frontend/node_modules