feat: implement textured line clear effects and refine UI alignment

- **Visual Effects**: Upgraded line clear particles to use the game's block texture instead of simple circles, matching the reference web game's aesthetic.
- **Particle Physics**: Tuned particle velocity, gravity, and fade rates for a more dynamic explosion effect.
- **Rendering Integration**: Updated [main.cpp](cci:7://file:///d:/Sites/Work/tetris/src/main.cpp:0:0-0:0) and `GameRenderer` to pass the block texture to the effect system and correctly trigger animations upon line completion.
- **Menu UI**: Fixed [MenuState](cci:1://file:///d:/Sites/Work/tetris/src/states/MenuState.cpp:19:0-19:55) layout calculations to use fixed logical dimensions (1200x1000), ensuring consistent centering and alignment of the logo, buttons, and settings icon across different window sizes.
- **Code Cleanup**: Refactored `PlayingState` to delegate effect triggering to the rendering layer where correct screen coordinates are available.

docs/REFACTORING_SOLID_PRINCIPLES.md

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+# SOLID Principles Refactoring Plan
+
+## Current Architecture Issues
+
+### 1. Single Responsibility Principle (SRP) Violations
+- `ApplicationManager` handles initialization, coordination, rendering coordination, and asset management
+- `Game` class mixes game logic with some presentation concerns
+
+### 2. Open/Closed Principle (OCP) Opportunities
+- Hard-coded piece types and behaviors
+- Limited extensibility for new game modes or rule variations
+
+### 3. Dependency Inversion Principle (DIP) Missing
+- Concrete dependencies instead of interfaces
+- Direct instantiation rather than dependency injection
+
+## Proposed Improvements
+
+### 1. Extract Interfaces
+
+```cpp
+// src/core/interfaces/IRenderer.h
+class IRenderer {
+public:
+    virtual ~IRenderer() = default;
+    virtual void clear(uint8_t r, uint8_t g, uint8_t b, uint8_t a) = 0;
+    virtual void present() = 0;
+    virtual SDL_Renderer* getSDLRenderer() = 0;
+};
+
+// src/core/interfaces/IAudioSystem.h
+class IAudioSystem {
+public:
+    virtual ~IAudioSystem() = default;
+    virtual void playSound(const std::string& name) = 0;
+    virtual void playMusic(const std::string& name) = 0;
+    virtual void setMasterVolume(float volume) = 0;
+};
+
+// src/core/interfaces/IAssetLoader.h
+class IAssetLoader {
+public:
+    virtual ~IAssetLoader() = default;
+    virtual SDL_Texture* loadTexture(const std::string& path) = 0;
+    virtual void loadFont(const std::string& name, const std::string& path, int size) = 0;
+};
+```
+
+### 2. Dependency Injection Container
+
+```cpp
+// src/core/ServiceContainer.h
+class ServiceContainer {
+private:
+    std::unordered_map<std::type_index, std::shared_ptr<void>> services;
+    
+public:
+    template<typename T>
+    void registerService(std::shared_ptr<T> service) {
+        services[std::type_index(typeid(T))] = service;
+    }
+    
+    template<typename T>
+    std::shared_ptr<T> getService() {
+        auto it = services.find(std::type_index(typeid(T)));
+        if (it != services.end()) {
+            return std::static_pointer_cast<T>(it->second);
+        }
+        return nullptr;
+    }
+};
+```
+
+### 3. Break Down ApplicationManager
+
+```cpp
+// src/core/ApplicationLifecycle.h
+class ApplicationLifecycle {
+public:
+    bool initialize(int argc, char* argv[]);
+    void run();
+    void shutdown();
+};
+
+// src/core/SystemCoordinator.h
+class SystemCoordinator {
+public:
+    void initializeSystems(ServiceContainer& container);
+    void updateSystems(double deltaTime);
+    void shutdownSystems();
+};
+```
+
+### 4. Strategy Pattern for Game Rules
+
+```cpp
+// src/gameplay/interfaces/IGameRules.h
+class IGameRules {
+public:
+    virtual ~IGameRules() = default;
+    virtual int calculateScore(int linesCleared, int level) = 0;
+    virtual double getGravitySpeed(int level) = 0;
+    virtual bool shouldLevelUp(int lines) = 0;
+};
+
+// src/gameplay/rules/ClassicTetrisRules.h
+class ClassicTetrisRules : public IGameRules {
+public:
+    int calculateScore(int linesCleared, int level) override;
+    double getGravitySpeed(int level) override;
+    bool shouldLevelUp(int lines) override;
+};
+```
+
+## Implementation Priority
+
+1. **Phase 1**: Extract core interfaces (IRenderer, IAudioSystem)
+2. **Phase 2**: Implement dependency injection container
+3. **Phase 3**: Break down ApplicationManager responsibilities
+4. **Phase 4**: Add strategy patterns for game rules
+5. **Phase 5**: Improve testability with mock implementations
+
+## Benefits
+
+- **Testability**: Easy to mock dependencies for unit tests
+- **Extensibility**: New features without modifying existing code
+- **Maintainability**: Clear responsibilities and loose coupling
+- **Flexibility**: Easy to swap implementations (e.g., different renderers)