Minimize hides only that window, Show wIRC main tray item, remember hidden main, bump to 0.1.15

- Minimizing a window hides only that window to the tray. The other windows stay
  on the desktop. Win+D still hides everything.
- Tray left click shows every hidden window at its old position, or hides them
  all if none are hidden.
- The tray menu has a new Show wIRC main item that brings back just wIRC main.
- If wIRC main was hidden when wIRC quit, it starts hidden next time and the
  servers that were connected reconnect by themselves, so their channel windows
  open without wIRC main.

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

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "com.tpuahsiew.wirc"
-version = "0.1.14"
+version = "0.1.15"
 
 // No project-level repositories{} block here: settings.gradle.kts sets
 // dependencyResolutionManagement.repositoriesMode = FAIL_ON_PROJECT_REPOS and already
@@ -40,7 +40,7 @@ compose.desktop {
             appResourcesRootDir.set(project.file("installerResources"))
             targetFormats(TargetFormat.Msi, TargetFormat.Exe)
             packageName = "wIRC"
-            packageVersion = "0.1.14"
+            packageVersion = "0.1.15"
             windows {
                 menuGroup = "wIRC"
                 upgradeUuid = "8f14e45f-ceea-4a5e-9c3b-5b1f0e8c2b7a"