Migrate from Next.js to SvelteKit

- Replace Next.js app with SvelteKit + adapter-node
- basePath /bodenfeuchte configured in svelte.config.js
- MQTT listener starts via hooks.server.ts on server boot
- Chart.js replaces Recharts for the moisture graph
- Dockerfile simplified: single build step, node build output
- Removed custom server.ts (no longer needed)

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

tsconfig.json

@@ -1,34 +1,20 @@
 {
-  "compilerOptions": {
-    "target": "ES2017",
-    "lib": ["dom", "dom.iterable", "esnext"],
-    "allowJs": true,
-    "skipLibCheck": true,
-    "strict": true,
-    "noEmit": true,
-    "esModuleInterop": true,
-    "module": "esnext",
-    "moduleResolution": "bundler",
-    "resolveJsonModule": true,
-    "isolatedModules": true,
-    "jsx": "react-jsx",
-    "incremental": true,
-    "plugins": [
-      {
-        "name": "next"
-      }
-    ],
-    "paths": {
-      "@/*": ["./*"]
-    }
-  },
-  "include": [
-    "next-env.d.ts",
-    "**/*.ts",
-    "**/*.tsx",
-    ".next/types/**/*.ts",
-    ".next/dev/types/**/*.ts",
-    "**/*.mts"
-  ],
-  "exclude": ["node_modules"]
+	"extends": "./.svelte-kit/tsconfig.json",
+	"compilerOptions": {
+		"rewriteRelativeImportExtensions": true,
+		"allowJs": true,
+		"checkJs": true,
+		"esModuleInterop": true,
+		"forceConsistentCasingInFileNames": true,
+		"resolveJsonModule": true,
+		"skipLibCheck": true,
+		"sourceMap": true,
+		"strict": true,
+		"moduleResolution": "bundler"
+	}
+	// Path aliases are handled by https://svelte.dev/docs/kit/configuration#alias
+	// except $lib which is handled by https://svelte.dev/docs/kit/configuration#files
+	//
+	// To make changes to top-level options such as include and exclude, we recommend extending
+	// the generated config; see https://svelte.dev/docs/kit/configuration#typescript
 }