feat(pathfinding): Add Greedy Best-First Search Algorithm

[Sanan507]

Overview

Add Greedy Best-First Search to the Pathfinding Arena. Unlike A* which balances path cost g(n) + heuristic h(n), Greedy BFS relies solely on the Manhattan distance heuristic h(n), providing a fast but non-optimal search for educational contrast.

Implementation Details & File Reference

• Algorithm Model: Create backend/src/main/java/com/algorithmrace/visualizer/algorithms/pathfinding/GreedyBFSModel.java extending PathfindingModel.
  • Use priority queue ordered strictly by heuristic distance h(cell, end).
• Factory Registration: Add "Greedy Best-First" in PathfindingFactory.java.
• Complexity Catalog: Add entry in ComplexityCatalog.java highlighting non-optimality.
• Frontend Metadata: Add entry in frontend/src/data/algorithmMetadata.ts (complete: false, optimal: false).

Definition of Done

• Greedy Best-First Search appears in the Pathfinding Arena selector.
• Visually demonstrates aggressive target-seeking movement that can get trapped by obstacles.
• Metadata indicates optimal: false.

Skill Level

Good first issue — straightforward heuristic priority queue implementation.