Add: Memory Heap Detective quest

[Akshatshukla-25]

What does this PR do?

Closes #813

Adds Memory Heap Detective (quests/memory-heap-detective.html) under the JavaScript Fundamentals category. The quest is an interactive memory profiling and garbage collection diagnostic simulator where players inspect live V8-style Heap Graph snapshots, trace retainer paths from GC roots, identify memory leaks (detached DOM nodes, uncleared timers, dangling listeners), and apply code patches to trigger garbage collection before memory limits explode.

Type of Change

• New tool / quest
• Enhancement to existing tool
• Bug fix
• Documentation update
• Build system / infrastructure

Screenshot

Checklist

• I have read the Contributing Guide
• My branch follows the naming convention (add/tool-name, feat/description, or fix/description)
• I have tested my changes locally in at least one modern browser

For new tools / quests:

• The quest is a single self-contained .html file in the quests/ folder
• The filename is kebab-case (memory-heap-detective.html)
• I added an entry to data/quests.json with all required fields
• I added a screenshot as quests/memory-heap-detective.png next to the HTML file
• No JS frameworks or heavy UI libraries
• I ran node scripts/sort-norm.js data/quests.json to sort and normalize the quests registry
• I ran node scripts/build.js and verified the landing page renders correctly