feat: Phase 1 — Projektstruktur, DB-Schema, Auth-System

- Vollständige Verzeichnisstruktur gemäß CLAUDE.md
- Express-Server mit Helmet, Sessions, Rate Limiting, SPA-Fallback
- SQLite-Schema (Migration v1): 10 Tabellen, updated_at-Triggers, Indizes
- Versioniertes Migrations-System (schema_migrations)
- Auth-Routen: Login, Logout, /me, Admin-User-CRUD
- Frontend App-Shell: SPA-Router, API-Client, Design-System (CSS Tokens)
- PWA: Service Worker, Web App Manifest
- Setup-Script für ersten Admin-User (node setup.js)
- DB-Tests mit node:sqlite built-in: 29/29 bestanden
- Docker Compose + Dockerfile + Nginx-Beispielkonfiguration

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

public/manifest.json

@@ -0,0 +1,25 @@
+{
+  "name": "Oikos Familienplaner",
+  "short_name": "Oikos",
+  "description": "Selbstgehosteter Familienplaner für Kalender, Aufgaben, Einkauf und mehr.",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#F5F5F7",
+  "theme_color": "#007AFF",
+  "orientation": "portrait-primary",
+  "lang": "de",
+  "icons": [
+    {
+      "src": "/icons/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/icons/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }
+  ]
+}