v4.7.0: Add domain reputation/blocklist data source

- New DomainReputationResult model (status: clean/listed/unknown, listed
  sources, checked-at) and a `reputation(domain:)` method on ExternalDataService,
  mirroring the existing pluggable-URL enrichment pattern (ownership history,
  DNS history, extended subdomains, pricing). With no endpoint configured
  (the default; DomainDig ships no bundled third-party reputation dependency)
  it resolves to unavailable rather than "clean".
- New .reputation FeatureCapability/DataCapability, gated Pro+ like domainPricing.
- Threaded reputation/reputationError through LookupSnapshot and HistoryEntry
  (backward-compatible decode) so results persist with history entries.
- Auto-fetched in performLookup alongside pricing; surfaced as a "Reputation"
  info row, folded into DomainInsightEngine's risk score/factors and top-level
  insights (a listed domain raises risk score and adds a factor/insight), and
  exported in text, CSV, and JSON report output.
- Reputation-driven risk changes ride the existing change-severity pipeline, so
  a listed status flip is visible to monitoring the same way any other risk
  delta is, without bespoke monitoring wiring.

1 files changed, 5 insertions, 2 deletions

diff --git a/DomainDig/FeatureAccessService.swift b/DomainDig/FeatureAccessService.swift
index a601b33..1598354 100644
--- a/DomainDig/FeatureAccessService.swift
+++ b/DomainDig/FeatureAccessService.swift
@@ -32,6 +32,7 @@ enum FeatureCapability: String, CaseIterable, Identifiable {
     case dnsHistory
     case extendedSubdomains
     case domainPricing
+    case reputation
 
     var id: String { rawValue }
 
@@ -61,6 +62,8 @@ enum FeatureCapability: String, CaseIterable, Identifiable {
             return "Extended subdomains"
         case .domainPricing:
             return "Domain pricing"
+        case .reputation:
+            return "Domain reputation"
         }
     }
 }
@@ -157,7 +160,7 @@ enum FeatureAccessService {
         switch capability {
         case .workflows, .batchOperations, .automatedMonitoring, .localAlerts, .advancedExports:
             return "Available in Pro"
-        case .ownershipHistory, .dnsHistory, .extendedSubdomains, .domainPricing:
+        case .ownershipHistory, .dnsHistory, .extendedSubdomains, .domainPricing, .reputation:
             return "Available in Pro+"
         case .limitedTracking:
             return "Tracking is limited on Free"
@@ -219,7 +222,7 @@ enum FeatureAccessService {
     static func upgradePrompt(for capability: FeatureCapability) -> UpgradePromptContext {
         let title: String
         switch capability {
-        case .ownershipHistory, .dnsHistory, .extendedSubdomains, .domainPricing:
+        case .ownershipHistory, .dnsHistory, .extendedSubdomains, .domainPricing, .reputation:
             title = "Available in Pro+"
         default:
             title = "Available in Pro"