Heatmap solver is now a worker

- Android app now requests root (purpose still unknown)
- Android app starts on boot
- Frontend is now a PWA (purpose still unknown)

frontend/tsconfig.worker.json

@@ -0,0 +1,15 @@
+/* To learn more about this file see: https://angular.io/config/tsconfig. */
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "./out-tsc/worker",
+    "lib": [
+      "es2018",
+      "webworker"
+    ],
+    "types": []
+  },
+  "include": [
+    "src/**/*.worker.ts"
+  ]
+}