fix: display story age from firstSeenAt, not updatedAt

Old stories were reading "1 hr ago" because updatedAt bumps every time
the backend attaches another article to a cluster, however loosely
related. firstSeenAt is when the cluster actually first appeared and
is already in the API response — just wasn't decoded.

Verified live: story_1a37c858235b (F1 Austria GP recap) has
firstSeenAt 2026-06-16 but updatedAt 2026-07-11, freshnessScore 0.96 —
looked brand new despite being 25 days old. Also confirmed the API's
isStale field is unusable as a stopgap (always false regardless of age).

Ranking still surfaces old stories at the top — that's server-side
(signalScore/freshnessScore) and out of scope for the client per the
architecture rule against re-ranking. Logged in BACKLOG #15.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jarvis/Models/Models.swift

@@ -61,6 +61,11 @@ struct StorySummary: Codable, Identifiable, Hashable {
     let conflict: String?
     let updatedAt: Date
     let createdAt: Date
+    /// When the cluster first appeared. `updatedAt` bumps on every article the
+    /// backend attaches to the cluster (even a loosely-related one), so it can
+    /// read "1 hr ago" on stories that are actually weeks old — `firstSeenAt`
+    /// is the honest age. Optional so decoding tolerates older API responses.
+    let firstSeenAt: Date?
 }
 
 struct ScoreBreakdown: Codable, Hashable {
@@ -185,6 +190,10 @@ final class CachedStory {
     /// Original publish timestamp. Defaults to updatedAt for rows cached before
     /// this field was added — SwiftData handles the automatic migration.
     var createdAt: Date = Date()
+    /// When the cluster first appeared — the honest age, unlike `updatedAt` which
+    /// bumps whenever the backend attaches another article. Defaults to `updatedAt`
+    /// for rows cached before this field was added.
+    var firstSeenAt: Date = Date()
     var cachedAt: Date
 
     init(from summary: StorySummary) {
@@ -199,6 +208,7 @@ final class CachedStory {
         self.conflict = summary.conflict
         self.updatedAt = summary.updatedAt
         self.createdAt = summary.createdAt
+        self.firstSeenAt = summary.firstSeenAt ?? summary.updatedAt
         self.cachedAt = Date()
     }
 }

Jarvis/Store/StoryStore.swift

@@ -312,7 +312,8 @@ final class StoryStore: ObservableObject {
             consensus: old.consensus,
             conflict: old.conflict,
             updatedAt: old.updatedAt,
-            createdAt: old.createdAt
+            createdAt: old.createdAt,
+            firstSeenAt: old.firstSeenAt
         )
         stories[idx] = updated
         stories.sort(by: StorySummary.feedOrder)

Jarvis/Views/Home/SignalFeedView.swift

@@ -481,7 +481,7 @@ struct SignalFeedView: View {
                 if !story.sources.isEmpty {
                     SourceChips(names: story.sources.map(\.name), total: story.sourceCount)
                 }
-                Text("\(story.sourceCount) sources · \(story.updatedAt.timeAgoShort()) ago")
+                Text("\(story.sourceCount) sources · \((story.firstSeenAt ?? story.updatedAt).timeAgoShort()) ago")
                     .font(.system(size: 11, weight: .regular, design: .monospaced))
                     .foregroundStyle(Palette.tertiaryText)
             }
@@ -768,7 +768,8 @@ extension StorySummary {
             consensus: cached.consensus,
             conflict: cached.conflict,
             updatedAt: cached.updatedAt,
-            createdAt: cached.createdAt
+            createdAt: cached.createdAt,
+            firstSeenAt: cached.firstSeenAt
         )
     }
 }

Jarvis/Views/Home/StoryRowView.swift

@@ -99,7 +99,11 @@ struct StoryRowView: View {
 
     private var metaLine: String {
         let sources = "\(story.sourceCount) source\(story.sourceCount == 1 ? "" : "s")"
-        return "\(sources) · \(Topic.label(story.topic)) · \(story.updatedAt.timeAgoShort()) ago"
+        // firstSeenAt is when the cluster appeared — updatedAt bumps on every
+        // article the backend attaches, so it can read "just now" on stories
+        // that are actually weeks old.
+        let age = (story.firstSeenAt ?? story.updatedAt).timeAgoShort()
+        return "\(sources) · \(Topic.label(story.topic)) · \(age) ago"
     }
 }
 
@@ -117,7 +121,8 @@ struct StoryRowView: View {
                     id: "\(score)", headline: "Bank of Uganda cuts interest rates by 50 basis points",
                     summary: "", topic: "finance", tags: ["finance"], signalScore: score, scoreBreakdown: breakdown,
                     sourceCount: 7, sources: sources, consensus: nil, conflict: nil,
-                    updatedAt: Date().addingTimeInterval(-3600), createdAt: Date()),
+                    updatedAt: Date().addingTimeInterval(-3600), createdAt: Date(),
+                    firstSeenAt: Date().addingTimeInterval(-3600)),
                 isCached: score == 64
             )
         }