refactor(services): route logging through IPluginLogProxy

F12.2 step 5b — service cluster (~42 sites in 16 files):
MessageManager, GameFunctions/{Chat, GameFunctions, KeybindManager},
EmoteCache, PayloadHandler, AutoTellTabsService, FontManager, Commands,
Util/{WrapperUtil, AutoTranslate, MemoryUtil}, Message, Themes/ThemeRegistry,
Ipc/ExtraChat, Configuration.

The proxy interface gained Dalamud's params-overload signature
(messageTemplate + params object[]) to cover Configuration.cs:86 which
relies on Serilog-style placeholders.

Verified: zero remaining Plugin.Log.X(...) call-sites in HellionChat/,
build green, build-suite 690/690.

HellionChat/Ipc/ExtraChat.cs

@@ -62,7 +62,10 @@ public sealed class ExtraChat : IDisposable
         catch (Exception ex)
         {
             // ExtraChat is optional; IPC failure is normal when the plugin isn't loaded.
-            Plugin.Log.Verbose(ex, "ExtraChat IPC initial state query failed (peer not loaded?)");
+            Plugin.LogProxy.Verbose(
+                ex,
+                "ExtraChat IPC initial state query failed (peer not loaded?)"
+            );
         }
     }