RegWatch frontend : React/Vite -> nginx + Docker/CI homelab

- URL d'API externalisée (VITE_API_URL bakée au build), plus de localhost en dur
- Dockerfile multi-stage pnpm build -> nginx (fallback SPA)
- docker-compose (Watchtower) + .gitea/workflows/build.yml

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/App.module.css

@@ -0,0 +1,26 @@
+.app {
+  min-height: 100vh;
+  width: 100%;
+  background-color: #f8fafc;
+  display: flex;
+  flex-direction: column;
+}
+
+.contentWrapper {
+  display: flex;
+  flex: 1;
+  min-height: 100vh;
+}
+
+.main {
+  flex: 1;
+  margin-left: 16rem;
+  padding: 2rem;
+  min-height: 100vh;
+}
+
+@media (max-width: 768px) {
+  .main {
+    margin-left: 0;
+  }
+}