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/macro_evaluator.hpp

@@ -0,0 +1,50 @@
+// MacroEvaluator — WoW macro conditional parser and evaluator.
+// Extracted from evaluateMacroConditionals() in chat_panel_commands.cpp.
+// Phase 4.4 of chat_panel_ref.md.
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace wowee {
+namespace ui {
+
+class IGameState;
+class IModifierState;
+
+/**
+ * Evaluates WoW-style macro conditional expressions.
+ *
+ * Syntax: [cond1,cond2] Spell1; [cond3] Spell2; DefaultSpell
+ *
+ * The first alternative whose conditions all evaluate true is returned.
+ * If no conditions match, returns "".
+ *
+ * @p targetOverride is set to a specific GUID if [target=X] or [@X]
+ * was in the matching conditions, or left as UINT64_MAX for "use normal target".
+ */
+class MacroEvaluator {
+public:
+    MacroEvaluator(IGameState& gameState, IModifierState& modState);
+
+    /**
+     * Evaluate a macro conditional string.
+     * @param rawArg         The conditional text (e.g. "[combat] Spell1; Spell2")
+     * @param targetOverride Output: set to target GUID if specified, or -1
+     * @return               The matched argument text, or "" if nothing matched
+     */
+    std::string evaluate(const std::string& rawArg, uint64_t& targetOverride) const;
+
+private:
+    /** Evaluate a single condition token (e.g. "combat", "mod:shift", "@focus"). */
+    bool evalCondition(const std::string& cond, uint64_t& tgt) const;
+
+    /** Resolve effective target GUID (follows @/target= overrides). */
+    uint64_t resolveEffectiveTarget(uint64_t tgt) const;
+
+    IGameState& gameState_;
+    IModifierState& modState_;
+};
+
+} // namespace ui
+} // namespace wowee