[US-02] Alternating shooting with feedback

Implementation Summary

This merge request implements the alternating shooting system for the Battleship game as described in Issue #2.

Features Implemented:

Core Game Logic:

• Turn-based shooting system with automatic alternation
• Hit/miss detection with proper feedback messages
• Duplicate shot prevention (cannot shoot same coordinate twice)
• Game over detection when all ships are sunk

User Interface:

• Console-based game interface with board display
• Real-time feedback for shots (HIT/MISS messages)
• Turn indication and game state display

Technical Implementation:

• Complete MVC architecture with model, service, and view layers
• Comprehensive test coverage for all acceptance criteria
• Proper error handling for invalid coordinates
• Game state management with player switching

Acceptance Criteria Verified:

✅ Criterion 1: When firing at A1 for the first time, a message appears showing hit or miss, and that field becomes marked.

• Implemented in Game.shoot() method with proper hit detection
• Verified by Issue2AcceptanceCriteriaTest.testFirstShotAtA1_ShowsHitMissAndMarksField()

✅ Criterion 2: When the same field is targeted again, the shot does not go through, and the next player acts.

• Implemented duplicate shot prevention in Game.shoot()
• Verified by Issue2AcceptanceCriteriaTest.testDuplicateShotAtSameField_ShouldNotGoThrough()

✅ Criterion 3: After one shot cycle finishes, the control changes so that only the other player can continue.

• Implemented automatic turn switching in Game.shoot()
• Verified by Issue2AcceptanceCriteriaTest.testControlChangesToOtherPlayer_AfterShotCycle()

Test Coverage:

• All acceptance criteria covered by dedicated test class
• Unit tests for individual components (Board, Game, Player, Ship)
• Integration tests for game flow
• Pipeline verification: ✅ Success (Pipeline #7357)

Files Modified/Created:

Model Layer:

• Game.java - Core game logic with turn management
• Player.java - Player state and board management
• Board.java - Board state and shot tracking
• Ship.java - Ship placement and health tracking
• Coordinate.java - Coordinate validation and conversion

Service Layer:

• GameService.java - Game flow and user interaction

View Layer:

• ConsoleView.java - CLI interface for game display

Test Coverage:

• Issue2AcceptanceCriteriaTest.java - All acceptance criteria
• GameTest.java - Game logic unit tests
• BoardTest.java - Board functionality tests
• CoordinateTest.java - Coordinate validation tests

Closes #2