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/views/LoginView.vue

@@ -0,0 +1,64 @@
+<template>
+  <div class="flex items-center justify-center px-4">
+    <form
+      class="flex w-full max-w-sm flex-col gap-4 rounded-xl border border-zinc-800 bg-zinc-900/60 p-6"
+      @submit.prevent="onSubmit"
+    >
+      <div class="flex items-center justify-between">
+        <h1 class="text-lg font-semibold text-zinc-100">{{ t('common.appName') }}</h1>
+        <LanguageSwitcher />
+      </div>
+      <p class="text-sm text-zinc-400">{{ t('login.title') }}</p>
+      <label class="flex flex-col gap-1 text-xs text-zinc-400">
+        {{ t('login.tokenLabel') }}
+        <input
+          v-model="token"
+          type="password"
+          class="input font-mono"
+          :placeholder="t('login.tokenPlaceholder')"
+          autocomplete="current-password"
+          autofocus
+          required
+        />
+      </label>
+      <p v-if="error" class="text-sm text-red-400">{{ error }}</p>
+      <button type="submit" class="btn-primary" :disabled="submitting || token.trim() === ''">
+        {{ submitting ? t('login.submitting') : t('login.submit') }}
+      </button>
+    </form>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref } from 'vue';
+import { useRoute, useRouter } from 'vue-router';
+import { useI18n } from 'vue-i18n';
+import { useAuthStore } from '../stores/auth';
+import { ApiError } from '../lib/api';
+import LanguageSwitcher from '../components/LanguageSwitcher.vue';
+
+const { t } = useI18n();
+const route = useRoute();
+const router = useRouter();
+const auth = useAuthStore();
+
+const token = ref('');
+const error = ref<string | null>(null);
+const submitting = ref(false);
+
+async function onSubmit(): Promise<void> {
+  submitting.value = true;
+  error.value = null;
+  try {
+    await auth.login(token.value.trim());
+    const redirect = typeof route.query.redirect === 'string' ? route.query.redirect : '/';
+    await router.replace(redirect);
+  } catch (err) {
+    if (err instanceof ApiError && err.status === 401) error.value = t('login.invalidToken');
+    else if (err instanceof ApiError && err.status === 429) error.value = t('login.rateLimited');
+    else error.value = t('login.genericError', { status: err instanceof ApiError ? err.status : '?' });
+  } finally {
+    submitting.value = false;
+  }
+}
+</script>