feat: add TLD validation with real-time warnings

Implement comprehensive TLD validation that checks domain inputs against
the IANA TLD list and RDAP registry to provide context-aware error
messages and real-time UI warnings.

Key changes:
- Add tld-validation service that validates TLDs against IANA list and
  RDAP registry availability
- Show warning icons in LookupInput for invalid TLDs (error) and valid
  TLDs without RDAP support (warning) with explanatory tooltips
- Enhance error messages in getRegistryURL to differentiate between
  invalid TLDs, valid TLDs without RDAP, and malformed domains
- Add NotFoundError class for better 404 handling with context-specific
  messages per target type (domain, IP, ASN, entity, TLD)
- Make getRegistryURL async to support TLD validation in error path
- Add comprehensive test coverage for TLD validation and error messages
- Track TLD warning displays in telemetry

This improves UX by catching common mistakes (typos, non-existent TLDs,
reserved TLDs) before query execution and providing clear guidance.

src/pages/index.tsx

@@ -30,10 +30,16 @@ const Index: NextPage = () => {
 		[router]
 	);
 
-	const { error, target, setTarget, setTargetType, submit, currentType, manualType } = useLookup(
-		undefined,
-		handleUrlUpdate
-	);
+	const {
+		error,
+		target,
+		setTarget,
+		setTargetType,
+		submit,
+		currentType,
+		manualType,
+		tldValidation,
+	} = useLookup(undefined, handleUrlUpdate);
 
 	// Parse URL parameters on mount and auto-execute query if present
 	useEffect(() => {
@@ -143,6 +149,7 @@ const Index: NextPage = () => {
 						<LookupInput
 							isLoading={isLoading}
 							detectedType={currentType}
+							tldValidation={tldValidation}
 							shareableUrl={
 								response.isJust && target && typeof window !== "undefined"
 									? buildShareableUrl(window.location.origin, target, manualType)