feat(graph): add Prim's Minimum Spanning Tree Visualizer with frontier and visited panels

[SUJALGOYALL]

Prim’s Minimum Spanning Tree Visualizer — Frontier and Visited Panels

Description

This pull request introduces a complete Prim’s Minimum Spanning Tree (MST) Visualizer to the Graph Algorithms module.

Key Features Added

• Interactive graph building:
  • Double-click to add nodes
  • Click two nodes to add weighted edges
• Start Node Selector for Prim’s algorithm
• Step-by-step visualization using a generator-based animation flow
• Real-time UI panels:
  • ✅ Visited Nodes Panel
  • ✅ Frontier (Min-Edge Priority Queue) Panel
• Edge color transitions:
  • Blue → considering
  • Green → added to MST
  • Red → skipped (cycle prevention)
• Status indicator + step counter
• Reset option to clear the canvas
• Styling and behavior fully match the existing Kruskal / BFS / DFS visualizers

This implementation follows the existing project architecture (/algorithms/graph, /components/graph, /pages/graph) and integrates seamlessly within GraphPage.jsx through the dropdown-based algorithm selector.

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Semver Changes

• Patch (bug fix, no new features)
• Minor (new features, no breaking changes)
• Major (breaking changes)

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Issues

This PR closes the feature request for:
Prim’s Minimum Spanning Tree Visualizer

Closes #83

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Checklist

• I have read the Contributing Guidelines.