style: align v1.4.5 additions with HellionChat conventions

Pattern-adherence pass after the cycle's code commits:

- ChatLogWindow.cs: NotifiedDrawFailure renamed from
  _notifiedDrawFailure. The file's per-window state flags (DrewThisFrame,
  WasDocked, Activate, PlayedClosingSound, …) all use PascalCase
  without underscore prefix; the new flag now matches that
- Plugin.cs: trim the session-only RemoveAll comment from 5 lines to 2
  and add the standard TEST-MIRROR pointer line. Same shape as
  AutoTellTabsService.cs:28 and the other six TEST-MIRROR sites
- InputHistoryService.cs: add the TEST-MIRROR pointer for the new
  Build-Suite tests

HellionChat/Plugin.cs

@@ -164,11 +164,9 @@ public sealed class Plugin : IAsyncDalamudPlugin
             );
         }
 
-        // Auto-Tell-Tabs are session-only: their messages are usually
-        // privacy-filtered and resurrecting an empty tab from a crashed
-        // session would trigger DB-reconstruction on the next load. The
-        // TempTabCounter then re-pegs the snapshot from the stripped list in
-        // AutoTellTabsService.Initialize. (F2.3 — TEST-MIRROR in Build-Suite.)
+        // Session-only tabs are stripped on every load; AutoTellTabsService.Initialize
+        // then re-pegs TempTabCounter from the stripped list, not the pre-strip snapshot.
+        // TEST-MIRROR: ../../Hellion Build test/_Helpers/TempTabCounterTests.cs
         Config.Tabs.RemoveAll(t => t.IsTempTab);
 
         LanguageChanged(Interface.UiLanguage);