feat(monitoring): attribute SaaS citations by registrable domain

Persist host/registrable_domain/site_key on monitoring article URL
aliases, populate them on desktop-publish completion, and use them in
the citation pipeline to count how often SaaS-published content
appears as a citation source. Expose a /citation-summary endpoint with
a 7/30-day window switch and surface the new source-share metrics in
the tracking dashboard.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/i18n/messages/en-US.ts

@@ -432,7 +432,10 @@ const enUS = {
     backToQuestions: "Back to questions",
     citationRanking: "Citation Ranking",
     citationRankingTitle: "Citation Ranking",
-    citationRankingHint: "Track how often content published from this system appears across model answers.",
+    citationRankingHint: "Attribute SaaS-published content by registrable domain across model citation sources.",
+    citationWindow7: "Last 7 days",
+    citationWindow30: "Last 30 days",
+    citationWindowLabel: "Last {days} days",
     citedArticles: "Cited Articles",
     citedArticlesTitle: "Cited Articles",
     answerContent: "Answer Content",
@@ -492,6 +495,7 @@ const enUS = {
       citedAnswers: "Cited Answers",
       citedArticles: "Cited Articles",
       citationRate: "Citation Rate",
+      saasSourceRate: "Source Share",
       citations: "Citations",
       sourcePlatform: "Source",
       channelName: "Channel",