feat(ipc): wire TypingIpc state from InputBar API

HellionChat/Ipc/TypingIpc.cs

@@ -34,11 +34,13 @@ internal sealed class TypingIpc : IDisposable
     private ChatInputState LastState;
     private bool HasState;
 
+    private readonly Ui.Components.InputBar _inputBar;
     private readonly ILogger<TypingIpc> _logger;
 
-    internal TypingIpc(Plugin plugin, ILogger<TypingIpc> logger)
+    internal TypingIpc(Plugin plugin, Ui.Components.InputBar inputBar, ILogger<TypingIpc> logger)
     {
         Plugin = plugin;
+        _inputBar = inputBar;
         _logger = logger;
 
         StateQueryGate = Plugin.Interface.GetIpcProvider<ChatInputState>(
@@ -62,26 +64,51 @@ internal sealed class TypingIpc : IDisposable
 
     private ChatInputState BuildState()
     {
-        // Input visibility and focus come back when the new chat layer
-        // exposes the matching state. The channel type still resolves
-        // from the active tab so IPC consumers can read it today.
         var usedChannel = Plugin.CurrentTab.CurrentChannel;
         var inputChannel = usedChannel.UseTempChannel
             ? usedChannel.TempChannel
             : usedChannel.Channel;
         var channelType = inputChannel.ToChatType();
 
+        // `Plugin` here is the instance property on TypingIpc (TypingIpc.cs:18
+        // `private Plugin Plugin { get; }`), NOT the type `HellionChat.Plugin`.
+        // C# resolves `Plugin.MainWindow` as `this.Plugin.MainWindow` because
+        // the instance property shadows the type name inside this class. Do
+        // NOT switch to a type-qualified read (CS0120 — `MainWindow` is an
+        // instance member, not a static one). MainWindow is resolved in Phase-1
+        // (Plugin.cs:295) and never re-assigned, so `this.Plugin.MainWindow`
+        // is non-null by the time TypingIpc.Update() runs (HostedServices only
+        // start after Phase-1). The `null!`-suppression on the MainWindow
+        // property would let us drop the `?.`, but a null-safe read costs
+        // nothing at runtime and shields against a theoretical pre-Phase-1
+        // caller (a future IPC-pull that fires before HostedServices start).
+        // Defense in depth, no behaviour change for the production path.
+        var mainWindowOpen = this.Plugin.MainWindow?.IsOpen ?? false;
+
+        // Stale-state guard: InputBar._isFocused is only written in DrawInputField,
+        // which only runs while MainWindow is open. After the user closes the
+        // window, _isFocused freezes on the last value. _pendingMessage has the
+        // same stale problem — it is only cleared in TrySend (successful send)
+        // or ClearBuffer (manual reset), so closing MainWindow with non-empty
+        // buffer leaves PendingLength frozen above zero. Without gating all
+        // four state fields on mainWindowOpen, Cross-Plugin-Subscribers would
+        // keep seeing InputFocused: true / HasText: true / IsTyping: true /
+        // TextLength: N even though no input field exists.
+        var inputFocused = mainWindowOpen && _inputBar.IsFocused;
+        var hasText = mainWindowOpen && _inputBar.PendingLength > 0;
+        var textLength = mainWindowOpen ? _inputBar.PendingLength : 0;
+
         return (
-            InputVisible: false,
-            InputFocused: false,
-            HasText: false,
-            IsTyping: false,
-            TextLength: 0,
+            InputVisible: mainWindowOpen,
+            InputFocused: inputFocused,
+            HasText: hasText,
+            IsTyping: hasText,
+            TextLength: textLength,
             ChannelType: channelType
         );
     }
 
-    private ChatInputState GetState() => BuildState();
+    internal ChatInputState GetState() => BuildState();
 
     internal void Update()
     {

HellionChat/PluginHostFactory.cs

@@ -103,6 +103,7 @@ internal static class PluginHostFactory
         ));
         services.AddSingleton(sp => new TypingIpc(
             sp.GetRequiredService<Plugin>(),
+            sp.GetRequiredService<Ui.Components.InputBar>(),
             sp.GetRequiredService<ILogger<TypingIpc>>()
         ));