Refactor code style, comments, and robot implementations

Move UML PDF to doc/ and update .gitignore. Normalize includes,
whitespace and function signatures across headers/sources and add
concise class/function documentation. Fix RandomBot so the mine
limit is computed once and simplify DigDeepBot/SortBot mining logic.
Tidy World/Game initialization, error handling, and minor const/var
clarifications for readability and correctness

include/BaseRobot.h

@@ -4,25 +4,28 @@
 
 #include <string>
 
+/* Base robot implementation shared by all concrete robot types. */
 class BaseRobot : public Robot {
-    /* A robot base class that implements functions common to all robots. */
   public:
-    BaseRobot ( std::string name, int startX, int startY );
+    BaseRobot(std::string name, int startX, int startY);
 
-    void move ( int direction, const World &world ) override;
-    int decideNextMove ( const World &world ) const override;
+    void move(int direction, const World& world) override;
+    int decideNextMove(const World& world) const override;
 
-    void setPosition ( int x, int y ) override {
+    void setPosition(int x, int y) override {
         x_ = x;
         y_ = y;
     }
-    int getScore () const override { return score_; }
-    void addScore ( int points ) override { score_ += points; }
-    int getX () const override { return x_; }
-    int getY () const override { return y_; }
-    std::string getName () const override { return name_; }
+
+    int getScore() const override { return score_; }
+    void addScore(int points) override { score_ += points; }
+    int getX() const override { return x_; }
+    int getY() const override { return y_; }
+    std::string getName() const override { return name_; }
 
   protected:
-    int x_, y_, score_;
+    int x_;
+    int y_;
+    int score_;
     std::string name_;
 };