Expand Variables Question Database with Advanced Scenarios

[SyntaxSidekick]

The current variables section needs more comprehensive coverage of JavaScript variable concepts.

Current State:

• Basic var, let, const questions
• Simple hoisting scenarios

Needed Additions:

• 5 questions on temporal dead zone edge cases
• 3 questions on block scoping vs function scoping
• 4 questions on variable reassignment patterns
• 3 questions on variable shadowing
• 2 questions on global vs local scope conflicts

Acceptance Criteria:

• Add 17+ new variable questions to questionsDatabase.json
• Include beginner, intermediate, and advanced difficulty levels
• Each question must have clear explanations and hints
• Test all questions in console execution

Priority: High - Foundation topic that many other concepts build upon