refactor: extract spline math, consolidate packet parsing, decompose TransportManager

Extract CatmullRomSpline (include/math/spline.hpp, src/math/spline.cpp) as a
standalone, immutable, thread-safe spline module with O(log n) binary segment
search and fused position+tangent evaluation — replacing the duplicated O(n)
evalTimedCatmullRom/orientationFromTangent pair in TransportManager.

Consolidate 7 copies of spline packet parsing into shared functions in
game/spline_packet.{hpp,cpp}: parseMonsterMoveSplineBody (WotLK/TBC),
parseMonsterMoveSplineBodyVanilla, parseClassicMoveUpdateSpline,
parseWotlkMoveUpdateSpline, and decodePackedDelta. Named SplineFlag constants
replace magic hex literals throughout.

Extract TransportPathRepository (game/transport_path_repository.{hpp,cpp}) from
TransportManager — owns path data, DBC loading, and path inference. Paths stored
as PathEntry wrapping CatmullRomSpline + metadata (zOnly, fromDBC, worldCoords).
TransportManager reduced from ~1200 to ~500 lines, focused on transport lifecycle
and server sync.

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

include/ui/action_bar_panel.hpp

@@ -71,7 +71,7 @@ public:
     std::unordered_map<uint32_t, uint32_t> macroPrimarySpellCache_;
     size_t macroCacheSpellCount_ = 0;
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
 private:

include/ui/chat_panel.hpp

@@ -110,14 +110,14 @@ public:
     /** Reset all chat settings to defaults. */
     void restoreDefaults();
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
     /** Replace $g/$G and $n/$N gender/name placeholders in quest/chat text. */
     std::string replaceGenderPlaceholders(const std::string& text, game::GameHandler& gameHandler);
 
 private:
-    // Section 3.5: Injected UI services (Phase B singleton breaking)
+    // Injected UI services (Phase B singleton breaking)
     UIServices services_;
 
     // ---- Chat input state ----

include/ui/combat_ui.hpp

@@ -72,7 +72,7 @@ public:
     void renderThreatWindow(game::GameHandler& gameHandler);
     void renderBgScoreboard(game::GameHandler& gameHandler);
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
 private:

include/ui/dialog_manager.hpp

@@ -35,11 +35,11 @@ public:
     /// called in render() after reclaim corpse button
     void renderLateDialogs(game::GameHandler& gameHandler);
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
 private:
-    // Section 3.5: Injected UI services
+    // Injected UI services
     UIServices services_;
     // Common ImGui window flags for popup dialogs
     static constexpr ImGuiWindowFlags kDialogFlags =

include/ui/game_screen.hpp

@@ -55,7 +55,7 @@ public:
     // Dependency injection for extracted classes (Phase A singleton breaking)
     void setAppearanceComposer(core::AppearanceComposer* ac) { appearanceComposer_ = ac; }
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services);
 
 private:

include/ui/social_panel.hpp

@@ -73,7 +73,7 @@ public:
     void renderInspectWindow(game::GameHandler& gameHandler,
                              InventoryScreen& inventoryScreen);
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
 private:

include/ui/toast_manager.hpp

@@ -41,7 +41,7 @@ public:
     /// Fire achievement earned toast + sound
     void triggerAchievementToast(uint32_t achievementId, std::string name = {});
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
     // --- public state consumed by GameScreen for the golden burst overlay ---
@@ -49,7 +49,7 @@ public:
     uint32_t levelUpDisplayLevel = 0;
 
 private:
-    // Section 3.5: Injected UI services
+    // Injected UI services
     UIServices services_;
 
     // ---- Ding effect (own level-up) ----

include/ui/ui_manager.hpp

@@ -75,7 +75,7 @@ public:
         if (gameScreen) gameScreen->setAppearanceComposer(ac);
     }
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) {
         services_ = services;
         if (gameScreen) gameScreen->setServices(services);
@@ -86,7 +86,7 @@ public:
 
 private:
     core::Window* window = nullptr;
-    UIServices services_;  // Section 3.5: Injected services
+    UIServices services_;  // Injected services
 
     // UI Screens
     std::unique_ptr<AuthScreen> authScreen;

include/ui/ui_services.hpp

@@ -23,7 +23,7 @@ namespace ui {
 /**
  * UI Services - Dependency injection container for UI components.
  * 
- * Section 3.5: Break the singleton Phase B
+ * Break the singleton Phase B
  * 
  * Replaces Application::getInstance() calls throughout UI code.
  * Application creates this struct and injects it into UIManager,

include/ui/window_manager.hpp

@@ -174,7 +174,7 @@ public:
     std::unordered_map<uint32_t, ExtendedCostEntry> extendedCostCache_;
     bool extendedCostDbLoaded_ = false;
 
-    // Section 3.5: UIServices injection (Phase B singleton breaking)
+    // UIServices injection (Phase B singleton breaking)
     void setServices(const UIServices& services) { services_ = services; }
 
 private: