style: aplicar fixes de clang-tidy (todo excepto uppercase-literal-suffix)

Corregidos ~2570 issues automáticamente con clang-tidy --fix-errors
más ajustes manuales posteriores:

- modernize: designated-initializers, trailing-return-type, use-auto,
  avoid-c-arrays (→ std::array<>), use-ranges, use-emplace,
  deprecated-headers, use-equals-default, pass-by-value,
  return-braced-init-list, use-default-member-init
- readability: math-missing-parentheses, implicit-bool-conversion,
  braces-around-statements, isolate-declaration, use-std-min-max,
  identifier-naming, else-after-return, redundant-casting,
  convert-member-functions-to-static, make-member-function-const,
  static-accessed-through-instance
- performance: avoid-endl, unnecessary-value-param, type-promotion,
  inefficient-vector-operation
- dead code: XOR_KEY (orphan tras eliminar encryptData/decryptData),
  dead stores en engine.cpp y png_shape.cpp
- NOLINT justificado en 10 funciones con alta complejidad cognitiva
  (initialize, render, main, processEvents, update×3, performDemoAction,
  randomizeOnDemoStart, renderDebugHUD, AppLogo::update)

Compilación: gcc -Wall sin warnings. clang-tidy: 0 issues.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

source/shapes/atom_shape.hpp

@@ -6,17 +6,17 @@
 // Comportamiento: Núcleo estático + electrones orbitando en planos inclinados
 // Efecto: Modelo atómico clásico Bohr
 class AtomShape : public Shape {
-private:
-    float angle_y_ = 0.0f;            // Ángulo de rotación global en eje Y (rad)
-    float orbit_phase_ = 0.0f;        // Fase de rotación de electrones (rad)
-    float nucleus_radius_ = 0.0f;     // Radio del núcleo central (píxeles)
-    float orbit_radius_ = 0.0f;       // Radio de las órbitas (píxeles)
-    int num_points_ = 0;              // Cantidad total de puntos
+    private:
+        float angle_y_ = 0.0f;         // Ángulo de rotación global en eje Y (rad)
+        float orbit_phase_ = 0.0f;     // Fase de rotación de electrones (rad)
+        float nucleus_radius_ = 0.0f;  // Radio del núcleo central (píxeles)
+        float orbit_radius_ = 0.0f;    // Radio de las órbitas (píxeles)
+        int num_points_ = 0;           // Cantidad total de puntos
 
-public:
-    void generatePoints(int num_points, float screen_width, float screen_height) override;
-    void update(float delta_time, float screen_width, float screen_height) override;
-    void getPoint3D(int index, float& x, float& y, float& z) const override;
-    const char* getName() const override { return "ATOM"; }
-    float getScaleFactor(float screen_height) const override;
+    public:
+        void generatePoints(int num_points, float screen_width, float screen_height) override;
+        void update(float delta_time, float screen_width, float screen_height) override;
+        void getPoint3D(int index, float& x, float& y, float& z) const override;
+        const char* getName() const override { return "ATOM"; }
+        float getScaleFactor(float screen_height) const override;
 };