feat(update): notify about app updates on launch (chat banner) (#891)

Fires one silent update check per installed version at app start
(UpdateNoticeManager, release builds only) and shows a non-blocking
banner on the chat screen when a newer release exists. The About tab
adopts the launch result instead of re-pinging GitHub; dismissals
return on the next launch via the persisted latest tag.

Closes #890

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/test/java/com/m57/hermescontrol/data/local/AuthManagerTest.kt

@@ -134,6 +134,14 @@ class AuthManagerTest {
         verify { mockEditor.apply() }
     }
 
+    @Test
+    fun testGetAndSetLastKnownLatestTag() {
+        AuthManager.ensureDefaultProfile()
+        assertNull(AuthManager.getLastKnownLatestTag())
+        AuthManager.setLastKnownLatestTag("v1.22.0")
+        assertEquals("v1.22.0", AuthManager.getLastKnownLatestTag())
+    }
+
     @Test
     fun testGetHostAndPortFromBaseUrl() {
         AuthManager.setBaseUrl("https://10.0.0.1:9090/")