feat: migrated from process.env to getEnv() function with validation …

[07prajwal2000]

…layers

📌 Why

🎯 What Changed

🧪 How to Test / Verification

• Ran unit/integration tests (bun run test)
• Manual testing steps performed:

📋 Checklist

• Code follows project style & conventions
• Added/updated tests for new or modified logic
• Updated documentation (if applicable)
• PR title follows conventional format (e.g., feat(server): ..., fix(web): ...)