Make bare /quit disconnect only that server, keep windows open, bump to 0.1.9

/quit now disconnects the window's server without closing anything: every
buffer of that server and wIRC main get a "Disconnected" line, the server card
shows Disconnected with its Connect button, history is flushed to disk, and
there's no auto-reconnect. Connect rejoins the channels we were in (including
ones joined with /join, now tracked) into the still-open windows. Sending while
disconnected shows a "Not connected" line in that window. Exit wIRC still
disconnects everything and closes the app.

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

src/main/kotlin/irc/IrcConnection.kt

@@ -50,6 +50,9 @@ private fun translateOnConnectCommand(cmd: String): String {
 class IrcConnection(
     val config: ServerConfig,
     private val scope: CoroutineScope,
+    // Channels to rejoin on top of config.autoJoinChannels - the ones a previous connection
+    // to this server was in (see ConnectionManager.connect).
+    initialChannels: Collection<String> = emptyList(),
     private val onLine: (ParsedLine) -> Unit,
     private val onStatus: (String) -> Unit
 ) {
@@ -60,13 +63,17 @@ class IrcConnection(
     @Volatile private var socket: Socket? = null
     @Volatile private var writer: PrintWriter? = null
     private var readJob: Job? = null
-    private var wantConnected = false
+    // @Volatile: disconnect() clears it from the UI thread while the read loop checks it on
+    // an IO thread - it's what stops the loop from auto-reconnecting after a /quit.
+    @Volatile private var wantConnected = false
     private var backoffMillis = 2000L
 
     // Every channel we're currently in, whether from config.autoJoinChannels or joined
     // manually mid-session - so a reconnect rejoins everything, not just the original
     // auto-join list.
-    private val joinedChannels = java.util.concurrent.CopyOnWriteArraySet<String>()
+    private val joinedChannels = java.util.concurrent.CopyOnWriteArraySet<String>(initialChannels)
+
+    fun trackedChannels(): Set<String> = joinedChannels.toSet()
 
     // Guards runPostRegistration() against running twice for the same connection cycle
     // (376 and 422 are mutually exclusive per RFC, but this is cheap insurance) - reset
@@ -121,6 +128,9 @@ class IrcConnection(
                         Socket(config.host, config.port)
                     }
                     socket = sock
+                    // disconnect() can't interrupt a socket that's still being opened, so
+                    // check here before registering on a connection nobody wants anymore.
+                    ensureActive()
                     val out = PrintWriter(OutputStreamWriter(sock.getOutputStream(), Charsets.UTF_8), true)
                     writer = out
 
@@ -161,6 +171,9 @@ class IrcConnection(
                         handleRawLine(line)
                     }
                 } catch (e: Exception) {
+                    // After disconnect() the read fails because we closed the socket
+                    // ourselves - that's not an error worth reporting.
+                    if (!wantConnected) break
                     onStatus("Connection error: ${e.message}")
                     ircDebug(config.id, "connection dropped: ${e.message} - tracked channels at drop time: $joinedChannels")
                 } finally {
@@ -277,6 +290,9 @@ class IrcConnection(
             try { writer?.println("QUIT :leaving") } catch (_: Exception) {}
             readJob?.cancel()
             closeSocketQuietly()
+            // Ends the outbox consumer - this connection is never reused (a reconnect
+            // makes a new IrcConnection), so it would otherwise idle forever.
+            outbox.close()
         }
     }