Add scrollback text selection/copy, route all /whois output to wIRC main, bump to 0.1.8

- Scrollback (channel windows and wIRC main): mouse drag selection, double-click word,
  triple-click line, shift-click extend, Ctrl+C / Ctrl+Insert, Ctrl+A, Esc, and a
  right-click menu (Copy / Copy line / Select all). Copies one line per message.
  Clipboard writes go off the UI thread with a timeout, like the paste handler.
  Auto-scroll pauses while selecting and catches up once the selection is cleared.
- /whois: header, every reply line, related numerics (401/402/716/263...) and server or
  services notices arriving right after it all go to wIRC main under a bold
  "===== WHOIS <nick> (<server>) =====" header, counted by its unread indicator.

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

src/main/kotlin/data/Models.kt

@@ -48,7 +48,7 @@ data class IrcMessage(
 data class BufferKey(val serverId: String, val name: String)
 
 /**
- * wIRC main's own buffer: server messages (MOTD, numerics, errors, whois fallback) and
+ * wIRC main's own buffer: server messages (MOTD, numerics, errors, all whois output) and
  * services/server notices from every connected server. Server ids are built from the host
  * with every non-alphanumeric character replaced by '_' (see ServerEditDialog), so one can
  * never contain '-' - this id can't collide with a real server. Also used as the