Add PWA, service worker and Web Push

- Use new notification request/opt-in flow for push
- Implement unsubscribing
- Implement muting
- Implement emojis in title
- Add iOS specific PWA warning
- Don’t use websockets when web push is enabled
- Fix duplicate notifications
- Implement default web push setting
- Implement changing subscription type
- Implement web push subscription refresh
- Implement web push notification click

web/src/app/Prefs.js

@@ -1,33 +1,45 @@
-import db from "./db";
+import getDb from "./getDb";
 
 class Prefs {
+  constructor(db) {
+    this.db = db;
+  }
+
   async setSound(sound) {
-    db.prefs.put({ key: "sound", value: sound.toString() });
+    this.db.prefs.put({ key: "sound", value: sound.toString() });
   }
 
   async sound() {
-    const sound = await db.prefs.get("sound");
+    const sound = await this.db.prefs.get("sound");
     return sound ? sound.value : "ding";
   }
 
   async setMinPriority(minPriority) {
-    db.prefs.put({ key: "minPriority", value: minPriority.toString() });
+    this.db.prefs.put({ key: "minPriority", value: minPriority.toString() });
   }
 
   async minPriority() {
-    const minPriority = await db.prefs.get("minPriority");
+    const minPriority = await this.db.prefs.get("minPriority");
     return minPriority ? Number(minPriority.value) : 1;
   }
 
   async setDeleteAfter(deleteAfter) {
-    db.prefs.put({ key: "deleteAfter", value: deleteAfter.toString() });
+    this.db.prefs.put({ key: "deleteAfter", value: deleteAfter.toString() });
   }
 
   async deleteAfter() {
-    const deleteAfter = await db.prefs.get("deleteAfter");
+    const deleteAfter = await this.db.prefs.get("deleteAfter");
     return deleteAfter ? Number(deleteAfter.value) : 604800; // Default is one week
   }
+
+  async webPushDefaultEnabled() {
+    const obj = await this.db.prefs.get("webPushDefaultEnabled");
+    return obj?.value ?? "initial";
+  }
+
+  async setWebPushDefaultEnabled(enabled) {
+    await this.db.prefs.put({ key: "webPushDefaultEnabled", value: enabled ? "enabled" : "disabled" });
+  }
 }
 
-const prefs = new Prefs();
-export default prefs;
+export default new Prefs(getDb());