Add wIRC main scrollback, route services to it, remember window bounds, bump to 0.1.7

wIRC main scrollback
- The main window now has a "Server messages" scrollback using the same
  rendering and stick-to-bottom code as channel windows (extracted from
  ChannelScreen into a shared MessageScrollback composable).
- MOTD, numerics, errors, connection status, user modes, INVITE, ERROR,
  non-ACTION CTCP requests and notices/messages from services
  (NickServ, ChanServ, *Serv, Global, ...) and the server go there. Its
  history persists like any other buffer (history/wirc-main__main.json).
- Unread indicator: lines arriving while the main window is unfocused
  show as "N new" next to the label and in the window title/taskbar.

Private messages and /whois
- A PM or notice from a real user opens its query window, and reopens it
  if it was closed. Services and the server no longer open windows.
- /whois <nick> sends WHOIS and shows the formatted reply in the window
  it was typed in, or in wIRC main if that window has since closed.
- /me now sends a proper CTCP ACTION (the \x01 wrapper was missing).

Window position and size
- Main, channel and PM windows remember position and size in
  window_prefs.json under the existing "<serverId>__<name>" key (main
  uses "wirc-main__main"). The new windowX/windowY/windowWidth/
  windowHeight fields are optional, so older files still load.
- A saved position is only used if the window's title strip is on a
  connected monitor; otherwise, and for windows with no saved position,
  windows cascade from the primary screen's top-left with a 32dp offset.
- window_prefs.json is now written via a temp file + atomic move.

Cleanup
- Remove the TEMP DEBUG aliasDebug tracing, ServerRepository.upsert
  printlns and connmgr-debug printlns.

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

src/main/kotlin/data/ServerRepository.kt

@@ -42,16 +42,10 @@ class ServerRepository(rootDir: File) {
     }
 
     fun upsert(server: ServerConfig) {
-        // TEMP DEBUG (see task: on-connect identify command investigation) - confirms the
-        // Edit Server dialog's Save actually persists onConnectCommands, by writing then
-        // immediately re-reading the file back rather than trusting the in-memory value.
-        println("[ServerRepository] upsert(${server.id}): saving onConnectCommands=${server.onConnectCommands}")
         val current = loadAll().toMutableList()
         val idx = current.indexOfFirst { it.id == server.id }
         if (idx >= 0) current[idx] = server else current.add(server)
         saveAll(current)
-        val reloaded = loadAll().firstOrNull { it.id == server.id }
-        println("[ServerRepository] upsert(${server.id}): reloaded from disk onConnectCommands=${reloaded?.onConnectCommands}")
     }
 
     fun remove(serverId: String) {