Initial commit: SejeteralO water tarification platform

Full-stack app for participatory water pricing using Bezier curves.
- Backend: FastAPI + SQLAlchemy + SQLite with JWT auth
- Frontend: Nuxt 4 + TypeScript with interactive SVG editor
- Math engine: cubic Bezier tarification with Cardano solver
- Admin: commune management, household import, vote monitoring, CMS
- Citizen: interactive curve editor, vote submission
- Docker-compose deployment ready

Includes fixes for:
- Impact table snake_case/camelCase property mismatch
- CMS content backend API + frontend editor (was stub)
- Admin route protection middleware
- Public content display on commune page
- Vote confirmation page link fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/app/pages/login/commune.vue

@@ -0,0 +1,64 @@
+<template>
+  <div style="max-width: 420px; margin: 2rem auto;">
+    <div class="card">
+      <h2 style="margin-bottom: 0.5rem;">Espace commune</h2>
+      <p style="color: var(--color-text-muted); margin-bottom: 1.5rem; font-size: 0.875rem;">
+        Connectez-vous pour gérer les données de votre commune.
+      </p>
+
+      <div v-if="error" class="alert alert-error">{{ error }}</div>
+
+      <form @submit.prevent="login">
+        <div class="form-group">
+          <label>Email</label>
+          <input v-model="email" type="email" class="form-input" placeholder="contact@mairie.fr" required />
+        </div>
+        <div class="form-group">
+          <label>Mot de passe</label>
+          <input v-model="password" type="password" class="form-input" required />
+        </div>
+        <button type="submit" class="btn btn-primary" :disabled="loading" style="width: 100%;">
+          <span v-if="loading" class="spinner" style="width: 1rem; height: 1rem;"></span>
+          <span v-else>Se connecter</span>
+        </button>
+      </form>
+    </div>
+
+    <p style="text-align: center; margin-top: 1rem;">
+      <NuxtLink to="/">&larr; Retour à l'accueil</NuxtLink>
+    </p>
+  </div>
+</template>
+
+<script setup lang="ts">
+const authStore = useAuthStore()
+const router = useRouter()
+const api = useApi()
+
+const email = ref('')
+const password = ref('')
+const error = ref('')
+const loading = ref(false)
+
+async function login() {
+  error.value = ''
+  loading.value = true
+  try {
+    const data = await api.post<{ access_token: string; role: string; commune_slug: string | null }>(
+      '/auth/admin/login',
+      { email: email.value, password: password.value },
+    )
+    authStore.setAuth(data.access_token, data.role, data.commune_slug || undefined)
+
+    if (data.commune_slug) {
+      router.push(`/admin/communes/${data.commune_slug}`)
+    } else {
+      router.push('/admin')
+    }
+  } catch (e: any) {
+    error.value = e.message || 'Erreur de connexion'
+  } finally {
+    loading.value = false
+  }
+}
+</script>