android: add global search inline jump theme toggle and accessibility pass

android/CHANGELOG.md

@@ -417,3 +417,15 @@
   - joining discovered chats,
   - loading chat members/bans by chat id,
   - executing admin/member visibility actions from one place.
+
+### Step 68 - Search, inline jump, theme toggle, accessibility pass
+- Added global search baseline in chat list:
+  - users search (`/users/search`),
+  - messages search (`/messages/search`),
+  - chat discovery integration (`/chats/discover`).
+- Added inline search in chat screen with jump navigation (prev/next) and automatic scroll to matched message.
+- Added highlighted message state for active inline search result.
+- Added theme switching controls in settings (Light/Dark/System) via `AppCompatDelegate`.
+- Added accessibility refinements for key surfaces and controls:
+  - explicit content descriptions for avatars and tab-like controls,
+  - voice record button semantic label for TalkBack.