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.vue

@@ -0,0 +1,46 @@
+<template>
+  <div style="max-width: 500px; margin: 2rem auto;">
+    <div class="page-header" style="text-align: center;">
+      <h1>Connexion</h1>
+      <p style="color: var(--color-text-muted);">Choisissez votre espace.</p>
+    </div>
+
+    <div class="grid grid-2">
+      <NuxtLink to="/login/commune" class="card login-choice">
+        <h3>Commune</h3>
+        <p>Gérer les données et la tarification de votre commune.</p>
+      </NuxtLink>
+      <NuxtLink to="/login/admin" class="card login-choice">
+        <h3>Super Admin</h3>
+        <p>Gestion globale des communes et administrateurs.</p>
+      </NuxtLink>
+    </div>
+
+    <p style="text-align: center; margin-top: 1.5rem;">
+      <NuxtLink to="/">&larr; Retour à l'accueil</NuxtLink>
+    </p>
+  </div>
+</template>
+
+<style scoped>
+.login-choice {
+  text-align: center;
+  cursor: pointer;
+  transition: box-shadow 0.15s;
+}
+
+.login-choice:hover {
+  box-shadow: var(--shadow-md);
+  text-decoration: none;
+}
+
+.login-choice h3 {
+  color: var(--color-primary);
+  margin-bottom: 0.5rem;
+}
+
+.login-choice p {
+  font-size: 0.8rem;
+  color: var(--color-text-muted);
+}
+</style>