Feature/new prs base

[bobnik]

Shared Infrastructure for Upcoming Feature Branches

This PR adds shared graph algorithms, geometry utilities, and shape infrastructure in anticipation of multiple upcoming PRs. This has minor impact on existing shapes (e.g., TesselationTwist and Maze), and those shapes have been manually tested ahead of this merge.

• Add graph algorithms for connected components and Eulerian trail computation
• Add geometry utilities used by multiple features (centroid, point-in-polygon, etc.)
• Convert recursive Hierholzer's algorithm to iterative (prevents stack overflow)
• Refactor Maze and TessellationTwist to use new getEulerianTrail() API
• Add Union-Find data structure for optimal component bridging