refactor(chat): decompose into modular architecture, add GM commands, fix protocol

- Extract ChatPanel monolith into 15+ focused modules under ui/chat/
  (ChatInput, ChatTabManager, ChatTabCompleter, ChatMarkupParser,
  ChatMarkupRenderer, ChatCommandRegistry, ChatBubbleManager,
  ChatSettings, MacroEvaluator, GameStateAdapter, InputModifierAdapter)
- Split 2700-line chat_panel_commands.cpp into 11 command modules
- Add GM command handling: 190-command data table, dot-prefix interception,
  tab-completion, /gmhelp with category filter
- Fix ChatType enum to match WoW wire protocol (SAY=0x01 not 0x00);
  values 0x00-0x1B shared across Vanilla/TBC/WotLK
- Fix BG_SYSTEM_* values from 82-84 (UB in bitmask shifts) to 0x24-0x26
- Fix infinite Enter key loop after teleport (disable TOGGLE_CHAT repeat,
  add 2-frame input cooldown)
- Add tests: chat_markup_parser, chat_tab_completer, gm_commands,
  macro_evaluator

Signed-off-by: Pavel Okhlopkov <pavel.okhlopkov@flant.com>

include/ui/chat/game_state_adapter.hpp

@@ -0,0 +1,63 @@
+// GameStateAdapter — wraps GameHandler + Renderer to implement IGameState.
+// Phase 4.2 of chat_panel_ref.md.
+#pragma once
+
+#include "ui/chat/i_game_state.hpp"
+
+namespace wowee {
+namespace game { class GameHandler; }
+namespace rendering { class Renderer; }
+
+namespace ui {
+
+/**
+ * Concrete adapter from GameHandler + Renderer → IGameState.
+ * Flatten complex entity/aura queries into the simple IGameState interface.
+ */
+class GameStateAdapter : public IGameState {
+public:
+    GameStateAdapter(game::GameHandler& gameHandler, rendering::Renderer* renderer);
+
+    // --- GUIDs ---
+    uint64_t getPlayerGuid() const override;
+    uint64_t getTargetGuid() const override;
+    uint64_t getFocusGuid() const override;
+    uint64_t getPetGuid() const override;
+    uint64_t getMouseoverGuid() const override;
+
+    // --- Player state ---
+    bool isInCombat() const override;
+    bool isMounted() const override;
+    bool isSwimming() const override;
+    bool isFlying() const override;
+    bool isCasting() const override;
+    bool isChanneling() const override;
+    bool isStealthed() const override;
+    bool hasPet() const override;
+    bool isInGroup() const override;
+    bool isInRaid() const override;
+    bool isIndoors() const override;
+
+    // --- Numeric ---
+    uint8_t getActiveTalentSpec() const override;
+    uint32_t getVehicleId() const override;
+    uint32_t getCurrentCastSpellId() const override;
+
+    // --- Spell/aura ---
+    std::string getSpellName(uint32_t spellId) const override;
+    bool hasAuraByName(uint64_t targetGuid, const std::string& spellName,
+                       bool wantDebuff) const override;
+    bool hasFormAura() const override;
+
+    // --- Entity queries ---
+    bool entityExists(uint64_t guid) const override;
+    bool entityIsDead(uint64_t guid) const override;
+    bool entityIsHostile(uint64_t guid) const override;
+
+private:
+    game::GameHandler& gameHandler_;
+    rendering::Renderer* renderer_;
+};
+
+} // namespace ui
+} // namespace wowee