Initial commit: DNS Test - DNS health checking tool

Go backend (miekg/dns) + Nuxt 3 frontend (Tailwind CSS v4).

8 check categories, 52 checks total:
- Overview: @ record, WWW, MX with ASN/provider lookup
- Domain Registration: expiry, registrar (RDAP + whois fallback)
- Parent Delegation: NS records, glue, consistency
- Nameservers: 17 checks (reachability, auth, recursion, TCP/UDP, AXFR, etc.)
- SOA: serial consistency, timing values
- Mail (MX): 11 checks (CNAME, PTR, public IPs, consistency)
- Mail Auth: SPF, DKIM, DMARC
- WWW: A record, CNAME

Features:
- SSE streaming (results appear as each category completes)
- SQLite history (modernc.org/sqlite)
- Rate limiting, CORS, request logging
- Dark mode, responsive design

frontend/app/types/dns.ts

@@ -0,0 +1,31 @@
+export type CheckStatus = 'pass' | 'warn' | 'fail' | 'info'
+
+export interface CheckResult {
+  id: string
+  title: string
+  status: CheckStatus
+  message: string
+  details?: string[]
+  duration_ms: number
+}
+
+export interface Category {
+  name: string
+  title: string
+  checks: CheckResult[]
+}
+
+export interface Summary {
+  pass: number
+  warn: number
+  fail: number
+  info: number
+}
+
+export interface DnsReport {
+  domain: string
+  timestamp: string
+  duration_ms: number
+  summary: Summary
+  categories: Category[]
+}