Dev

[Rowrow620]

Description

This Pull Request completes 100% of the NeetCode 150 Roadmap (150 / 150 Problems Implemented) across all 18 topic categories!

Summary of Changes:

• Linked List Category (8/8 New Visualizers): Implemented Reorder List (#143), Remove Nth Node From End (feat: add clear button to search filter #19), Copy List with Random Pointer (#138), Add Two Numbers (build(deps): bump actions/upload-pages-artifact from 3 to 5 #2), Find the Duplicate Number (#287), LRU Cache (#146), Merge k Sorted Lists (feat: Add hover tooltip to playback speed slider #23), and Reverse Nodes in k-Group (Add confirmation dialog before resetting dashboard progress #25).
• Trees Category (7/7 New Visualizers): Implemented Binary Tree Level Order Traversal (#102), Binary Tree Right Side View (#199), Count Good Nodes in Binary Tree (#1448), Kth Smallest Element in a BST (#230), Construct Binary Tree from Preorder and Inorder Traversal (#105), Binary Tree Maximum Path Sum (#124), and Serialize and Deserialize Binary Tree (#297).
• Audit Gating System: Preserved public release audit status for verified core problems (Contains Duplicate, Two Sum, Valid Anagram) while unlocking all 150 problems in Developer Mode (cargo run -- --dev / ?dev=true).

Related Issues

N/A

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New problem visualizer audit / promotion (AuditStatus::Audited)
• New feature (non-breaking change adding functionality)
• Documentation update
• Refactoring / performance optimization

Verification Checklist

• Code compiles cleanly without errors
• cargo test passes 100% of unit tests
• cargo fmt --all -- --check complies with standard Rust formatting
• cargo clippy --all-targets -- -D warnings produces zero warnings
• Step visualizer tested locally in desktop mode (cargo run) and/or WebAssembly mode (trunk serve)