UX/UI redesign for the mobile WebView

- Compact top bar (logo, OASIS, user avatar with default fallback).
- Fixed bottom navigation (Search, Inbox, Write, Activity + Peers/Invites) with active state.
- Removed duplicated header nav buttons on mobile.
- Personal/Community submenus: single-open accordion.
- Activity filters grouped into quick modes + collapsible thematic groups.
- Private messages rendered as chat bubbles on mobile.
- Text fixes, full-width stacked tables, touch feedback; Activity group labels in 11 locales.
Mobile-scoped (mobile.css + views); desktop unaffected.

src/client/assets/translations/oasis_hi.js

@@ -1,6 +1,12 @@
 const { a, em, strong } = require('../../../server/node_modules/hyperaxe');
 module.exports = {
   hi: {
+    activityGroupCommunity: "समुदाय और शासन",
+    activityGroupOrg: "संगठन",
+    activityGroupComm: "संचार",
+    activityGroupEconomy: "अर्थव्यवस्था",
+    activityGroupMedia: "सामग्री और मीडिया",
+    activityGroupOther: "अन्य",
     languageName: "हिन्दी",
     shopOrderStatusPaid: "भुगतान प्राप्त",
     shopOrderStatusReceived: "प्राप्त",