P1 complete: web front, test suite, CI — acceptance ALL GREEN

Fan-out integration + fixes found by the test/acceptance pass:
- FIX ring-buffer: chunks >= capacity skipped bytes now count into the
  monotonic offset (invariant: stream byte k lives at k % capacity) —
  window order was corrupted on unaligned big chunks
- FIX auth: non-numeric cookie expiry no longer bypasses expiration
- FIX protocol: safe-integer validation on ack.bytes / hello.protocol
- FIX @fastify/websocket v11: websocket route must be registered in an
  encapsulated context after plugin load (handler got REST signature)
- FIX flow-control deadlock found by e2e acceptance: client only ACKs
  on data receipt, so pausing with an unACKed residue in (LOW,
  ACK_EVERY] stalled both sides at 0.9 MB. ACK_EVERY now 64 KiB (<=
  LOW invariant, tested) + trailing debounced ACK in the web client
- Web: Vue 3 + Vite + Pinia + Tailwind 4 + vue-i18n (EN/FR) + xterm 6
  (fit + webgl fallback), multiplexed ws-client with reconnect/backoff
  and resync epochs
- Tests: 100 vitest (protocol fuzz, ring edges, auth, pty-manager flow
  control with mocked pty, REST e2e) ; CI Node 22/24 + pack-smoke
- scripts/acceptance-p1.mjs: real daemon + real WS client — boot,
  login, attach, stdin, 10 MB flood w/ ACK (13.7 MB/1.9s, RSS bounded),
  brutal disconnect + replay resync, kill broadcast, SIGTERM drain

packages/web/src/App.vue

@@ -0,0 +1,20 @@
+<template>
+  <div class="flex h-full flex-col">
+    <div
+      v-if="wsReconnecting"
+      class="border-b border-amber-900/50 bg-amber-950/80 px-4 py-1.5 text-center text-xs text-amber-300"
+    >
+      {{ t('ws.reconnecting') }}
+    </div>
+    <RouterView class="min-h-0 flex-1" />
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue';
+import { useI18n } from 'vue-i18n';
+import { wsClient } from './lib/ws-client';
+
+const { t } = useI18n();
+const wsReconnecting = computed(() => wsClient.status.value === 'reconnecting');
+</script>