Sessions Integration Feature

Nucleic-Session: FC94353F-9F0D-4BCC-AD7C-0FB14E38C2E5
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Models/RemoteStore.swift

@@ -1188,6 +1188,60 @@ extension Data {
     }
 }
 
+extension DashboardSnapshot {
+    /// Merge every connected Mac's dashboard into one aggregate projection (mesh P3), so Home,
+    /// Projects, and To-Dos show all your Macs together: projects and to-dos concatenated, activity
+    /// summed per day, counts summed (active-days recomputed from the merged activity), subscription
+    /// usage taken from the first Mac that reports it (a user's Macs share one account, so their
+    /// windows match — summing would double-count), and provider status feeds unioned by provider
+    /// (provider status is global, not per-Mac).
+    static func merged(_ snapshots: some Collection<DashboardSnapshot>) -> DashboardSnapshot {
+        let snaps = Array(snapshots)
+        guard snaps.count != 1 else { return snaps[0] }
+        guard !snaps.isEmpty else { return .empty }
+
+        let projects = snaps.flatMap(\.projects)
+        let todos = snaps.flatMap(\.todos)
+
+        // Activity summed per start-of-day.
+        var byDay: [Date: (count: Int, tokens: Int)] = [:]
+        for snap in snaps {
+            for day in snap.activity {
+                let key = Calendar.current.startOfDay(for: day.day)
+                var entry = byDay[key] ?? (0, 0)
+                entry.count += day.count
+                entry.tokens += day.tokens
+                byDay[key] = entry
+            }
+        }
+        let activity = byDay
+            .map { ActivityDay(day: $0.key, count: $0.value.count, tokens: $0.value.tokens) }
+            .sorted { $0.day < $1.day }
+
+        let counts = DashboardCounts(
+            projects: projects.count,
+            chats: snaps.reduce(0) { $0 + $1.counts.chats },
+            activeChats: snaps.reduce(0) { $0 + $1.counts.activeChats },
+            messages: snaps.reduce(0) { $0 + $1.counts.messages },
+            activeDays: activity.filter { $0.count > 0 || $0.tokens > 0 }.count,
+            tokens: snaps.reduce(0) { $0 + $1.counts.tokens })
+
+        let usage = snaps.compactMap(\.usage).first
+
+        var seenProviders = Set<String>()
+        var statusFeeds: [WireStatusFeed] = []
+        for snap in snaps {
+            for feed in snap.statusFeeds where seenProviders.insert(feed.provider).inserted {
+                statusFeeds.append(feed)
+            }
+        }
+
+        return DashboardSnapshot(
+            counts: counts, activity: activity, projects: projects,
+            todos: todos, usage: usage, statusFeeds: statusFeeds)
+    }
+}
+
 extension WireSessionSummary {
     /// A copy with selected fields overridden — the demo simulator's only way to "mutate" a
     /// summary, whose stored properties are all `let`. Nullable fields use a double optional so a