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/i_game_state.hpp

@@ -0,0 +1,63 @@
+// IGameState — abstract interface for game state queries used by macro evaluation.
+// Allows unit testing with mock state. Phase 4.1 of chat_panel_ref.md.
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace wowee {
+namespace ui {
+
+/**
+ * Read-only view of game state for macro conditional evaluation.
+ *
+ * All entity/aura queries are flattened to simple types so callers
+ * don't need to depend on game::Entity, game::Unit, etc.
+ */
+class IGameState {
+public:
+    virtual ~IGameState() = default;
+
+    // --- GUIDs ---
+    virtual uint64_t getPlayerGuid() const = 0;
+    virtual uint64_t getTargetGuid() const = 0;
+    virtual uint64_t getFocusGuid() const = 0;
+    virtual uint64_t getPetGuid() const = 0;
+    virtual uint64_t getMouseoverGuid() const = 0;
+
+    // --- Player state booleans ---
+    virtual bool isInCombat() const = 0;
+    virtual bool isMounted() const = 0;
+    virtual bool isSwimming() const = 0;
+    virtual bool isFlying() const = 0;
+    virtual bool isCasting() const = 0;
+    virtual bool isChanneling() const = 0;
+    virtual bool isStealthed() const = 0;
+    virtual bool hasPet() const = 0;
+    virtual bool isInGroup() const = 0;
+    virtual bool isInRaid() const = 0;
+    virtual bool isIndoors() const = 0;
+
+    // --- Numeric state ---
+    virtual uint8_t getActiveTalentSpec() const = 0;   // 0-based index
+    virtual uint32_t getVehicleId() const = 0;
+    virtual uint32_t getCurrentCastSpellId() const = 0;
+
+    // --- Spell/aura queries ---
+    virtual std::string getSpellName(uint32_t spellId) const = 0;
+
+    /** Check if target (or player if guid==playerGuid) has a buff/debuff by name. */
+    virtual bool hasAuraByName(uint64_t targetGuid, const std::string& spellName,
+                               bool wantDebuff) const = 0;
+
+    /** Check if player has a form/stance aura (permanent aura, maxDurationMs == -1). */
+    virtual bool hasFormAura() const = 0;
+
+    // --- Entity queries (flattened, no Entity* exposure) ---
+    virtual bool entityExists(uint64_t guid) const = 0;
+    virtual bool entityIsDead(uint64_t guid) const = 0;
+    virtual bool entityIsHostile(uint64_t guid) const = 0;
+};
+
+} // namespace ui
+} // namespace wowee