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/AutoTellTabsService.cs

@@ -96,7 +96,7 @@ internal sealed class AutoTellTabsService : IDisposable
         if (partner == null)
         {
             // Diagnostics: helps detect regressions (FFXIV payload changes, new edge cases)
-            Plugin.Log.Warning(
+            Plugin.LogProxy.Warning(
                 $"[AutoTellTabs] Could not extract tell partner. type={message.Code.Type}, "
                     + $"senderChunks={message.Sender.Count}, contentChunks={message.Content.Count}, "
                     + $"senderSourcePayloads={message.SenderSource?.Payloads?.Count ?? 0}, "
@@ -300,7 +300,7 @@ internal sealed class AutoTellTabsService : IDisposable
         catch (Exception ex)
         {
             // Non-fatal: tab still spawns with visible error notice instead of silent history loss
-            Plugin.Log.Error(ex, "[AutoTellTabs] History preload failed");
+            Plugin.LogProxy.Error(ex, "[AutoTellTabs] History preload failed");
             tab.Messages.AddPrune(
                 MakeSystemMarker(HellionStrings.AutoTellTabs_HistoryLoadError),
                 MessageManager.MessageDisplayLimit