Add Swagger Documentation & API Logging

[Krishna-sm]

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🚀 PR: Add Swagger Documentation, Env Setup, API Logging & Air Dev Setup

🔧 Summary

This pull request introduces multiple improvements to the project’s development experience and API structure.

✅ What’s Added

• Swagger API Documentation
  Added full Swagger setup to auto-generate interactive API docs.

• Environment Variables Setup
  Introduced .env.example and environment variable loading system for better config management.

• New ServeMux + API Logging Middleware
  Implemented a custom ServeMux along with structured API request/response logs.

• Air Integration for Development
  Added Air config to enable live reload during development.

🎯 Why These Changes

• Improves API discoverability
• Standardizes config handling
• Makes debugging easier
• Speeds up local development workflow
• Moves the project toward a cleaner, production-ready structure

📁 Files Updated

• .air.toml
• .env.example
• main.go
• Swagger docs & handlers
• Logging middleware

📝 Notes

This PR does not change any existing API functionality — it only introduces tooling, structure, and developer-experience improvements.