feat(dns): added DNS Lookup Simulator tool

[Tech-Psycho95]

Summary

Adds a new DNS Lookup Simulator tool that allows users to query DNS records for any domain using secure DNS-over-HTTPS (DoH) providers.

Changes

New Files:

• app/api/dns-lookup/route.ts - Backend API endpoint
• app/components/developmentToolsComponent/dnsLookupSimulator.tsx - Frontend component

Modified Files:

• app/libs/constants.tsx - Added import, path, route, and homepage listing (Category177)
• app/libs/developmentToolsConstant.tsx - Added tool documentation and SEO metadata

Features

Frontend:

• Domain name input with Enter key support
• Record type dropdown (A, AAAA, CNAME, MX, TXT, NS)
• DNS provider selector (Cloudflare/Google)
• Loading spinner during queries
• Copy-to-clipboard for individual values and all records
• Color-coded record type badges
• Human-readable TTL formatting (e.g., "1h 30m")
• Error and empty state handling

Backend:

• Secure DNS-over-HTTPS queries via Cloudflare and Google
• Automatic provider fallback on failure
• Domain validation and sanitization
• MX record priority parsing
• Structured JSON response with TTL values
• 5-minute response caching

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Testing

1. Start dev server: npm run dev
2. Navigate to http://localhost:3000/dns-lookup-simulator
3. Enter google.com and click Lookup
4. Test different record types (MX, TXT, NS, etc.)
5. Test copy buttons and provider switching
6. Test error handling with invalid domains

API Usage

• GET /api/dns-lookup?domain=example.com&type=A&provider=cloudflare

Parameter	Required	Default	Values
domain	Yes	-	Any valid domain
type	No	A	A, AAAA, CNAME, MX, TXT, NS
provider	No	cloudflare	cloudflare, google

Screenshots

Testing Checklist

• Start dev server: npm run dev
• Navigate to http://localhost:3000/dns-lookup-simulator
• Tool is visible on homepage under "Dev Utils" or via search
• Enter google.com and click Lookup - results appear
• Test A record type - shows IPv4 addresses
• Test AAAA record type - shows IPv6 addresses
• Test MX record type - shows mail servers with priority
• Test TXT record type - shows text records
• Test NS record type - shows name servers
• Test CNAME record type
• Switch DNS provider to Google - lookup works
• Copy individual record value - copies to clipboard
• Copy All button - copies all records
• Clear button - clears domain and results
• Enter key triggers lookup
• Invalid domain shows error message
• Empty domain shows validation error
• Loading spinner appears during lookup
• Mobile responsive layout works

Closes Issue #31