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/components/charts/VoteOverlayChart.vue

@@ -0,0 +1,112 @@
+<template>
+  <div class="overlay-chart">
+    <svg :viewBox="`0 0 ${svgW} ${svgH}`" preserveAspectRatio="xMidYMid meet">
+      <!-- Grid -->
+      <g>
+        <line
+          v-for="v in gridVolumes"
+          :key="'gv' + v"
+          :x1="toSvgX(v)" :y1="toSvgY(0)" :x2="toSvgX(v)" :y2="toSvgY(pmax)"
+          stroke="#e2e8f0" stroke-width="0.5"
+        />
+        <line
+          v-for="p in gridPrices"
+          :key="'gp' + p"
+          :x1="toSvgX(0)" :y1="toSvgY(p)" :x2="toSvgX(vmax)" :y2="toSvgY(p)"
+          stroke="#e2e8f0" stroke-width="0.5"
+        />
+      </g>
+
+      <!-- Vote curves (semi-transparent) -->
+      <g v-for="(vote, i) in votes" :key="i">
+        <path :d="getVotePath(vote, 1)" fill="none" stroke="#3b82f6" stroke-width="1" opacity="0.3" />
+        <path :d="getVotePath(vote, 2)" fill="none" stroke="#ef4444" stroke-width="1" opacity="0.3" />
+      </g>
+
+      <!-- Median curve (if available) -->
+      <g v-if="medianVote">
+        <path :d="getVotePath(medianVote, 1)" fill="none" stroke="#1e40af" stroke-width="3" />
+        <path :d="getVotePath(medianVote, 2)" fill="none" stroke="#991b1b" stroke-width="3" />
+      </g>
+
+      <!-- Axis labels -->
+      <text :x="svgW / 2" :y="svgH - 2" text-anchor="middle" font-size="11" fill="#64748b">
+        Volume (m³)
+      </text>
+      <text :x="6" :y="12" font-size="11" fill="#64748b">€/m³</text>
+    </svg>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { paramsToControlPoints } from '~/utils/bezier-math'
+
+const props = defineProps<{
+  votes: Array<{ vinf: number; a: number; b: number; c: number; d: number; e: number; computed_p0?: number }>
+  slug: string
+}>()
+
+const api = useApi()
+
+const svgW = 600
+const svgH = 300
+const margin = { top: 15, right: 15, bottom: 25, left: 30 }
+const plotW = svgW - margin.left - margin.right
+const plotH = svgH - margin.top - margin.bottom
+
+const vmax = ref(2100)
+const pmax = ref(20)
+const medianVote = ref<any>(null)
+
+function toSvgX(v: number): number {
+  return margin.left + (v / vmax.value) * plotW
+}
+
+function toSvgY(p: number): number {
+  return margin.top + plotH - (p / pmax.value) * plotH
+}
+
+const gridVolumes = computed(() => {
+  const step = Math.ceil(vmax.value / 7 / 100) * 100
+  const arr = []
+  for (let v = step; v < vmax.value; v += step) arr.push(v)
+  return arr
+})
+
+const gridPrices = computed(() => {
+  const step = Math.ceil(pmax.value / 5)
+  const arr = []
+  for (let p = step; p < pmax.value; p += step) arr.push(p)
+  return arr
+})
+
+function getVotePath(vote: any, tier: number): string {
+  const p0 = vote.computed_p0 || 5
+  const cp = paramsToControlPoints(vote.vinf, vmax.value, pmax.value, p0, vote.a, vote.b, vote.c, vote.d, vote.e)
+
+  if (tier === 1) {
+    return `M ${toSvgX(cp.p1.x)} ${toSvgY(cp.p1.y)} C ${toSvgX(cp.p2.x)} ${toSvgY(cp.p2.y)}, ${toSvgX(cp.p3.x)} ${toSvgY(cp.p3.y)}, ${toSvgX(cp.p4.x)} ${toSvgY(cp.p4.y)}`
+  } else {
+    return `M ${toSvgX(cp.p4.x)} ${toSvgY(cp.p4.y)} C ${toSvgX(cp.p5.x)} ${toSvgY(cp.p5.y)}, ${toSvgX(cp.p6.x)} ${toSvgY(cp.p6.y)}, ${toSvgX(cp.p7.x)} ${toSvgY(cp.p7.y)}`
+  }
+}
+
+onMounted(async () => {
+  try {
+    const params = await api.get<any>(`/communes/${props.slug}/params`)
+    vmax.value = params.vmax
+    pmax.value = params.pmax
+  } catch {}
+
+  try {
+    medianVote.value = await api.get(`/communes/${props.slug}/votes/median`)
+  } catch {}
+})
+</script>
+
+<style scoped>
+.overlay-chart svg {
+  width: 100%;
+  height: auto;
+}
+</style>