Build Puzzle Versioning System

[Mkalbani]

Description

Implement a versioning layer for the puzzles module so that puzzle edits do not break active sessions or invalidate historical scores. Every time an admin modifies a puzzle's conditions, effects, or hints, a new version is created. Active sessions always reference the version that was live when they started, preserving result integrity across the game's full history.

Acceptance Criteria

• A PuzzleVersion entity stores a full snapshot of puzzle data with a version number and createdAt
• PATCH /puzzles/:id creates a new version instead of mutating the existing record
• Sessions store a puzzleVersionId reference at creation time
• GET /puzzles/:id/versions (admin-only) returns the full version history
• GET /puzzles/:id/versions/:versionId returns a specific version snapshot
• Scoring and evaluation always use the version attached to the session, not the latest
• Rollback endpoint POST /puzzles/:id/rollback/:versionId restores a previous version as the latest
• Unit tests cover version creation on edit, session version pinning, and rollback

[Dickson2015]

The issue description is crystal clear. Maintainer I would love to work on this issue.

[OAKVISUALZ]

Please assign me this issue.