Notify of pokes and private messages on Android, with TeamSpeak's sounds

While the app is out of sight, a poke or a private message posts a
notification; a message's one gathers the conversation, takes a reply
inline and opens its chat. The notifications are silent, as the sound
pack already plays TeamSpeak's own sound for either.

The build bundles the sound packs of the TeamSpeak 3 client found next
to the checkout (or at ts3.client.dir / TS3_CLIENT_DIR), unpacked into
the profile once per app version. Sound Settings picks the pack and its
volume, and speech packs talk through the phone's text-to-speech.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ts3-client/core/src/main/java/com/ts3client/text/BBCode.java

@@ -74,6 +74,11 @@ public final class BBCode {
         return out.toString();
     }
 
+    /** The text BBCode reads as, markup dropped, for places that show no formatting. */
+    public static String toPlain(String input) {
+        return HtmlText.plain(toHtml(input));
+    }
+
     /**
      * Renders text carrying {@code [url=…]…[/url]} links and nothing else: everything
      * outside those tags stays literal. The server log is written this way, so that a

ts3-client/core/src/test/java/com/ts3client/text/BBCodePlainTest.java

@@ -0,0 +1,15 @@
+package com.ts3client.text;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/** Messages shown where no formatting renders, such as a system notification. */
+class BBCodePlainTest {
+
+    @Test
+    void dropsMarkupAndKeepsText() {
+        assertEquals("Hello bold & <tags> and a link",
+                BBCode.toPlain("Hello [b]bold[/b] & <tags> and [url=https://x.y]a link[/url]"));
+    }
+}