initial commit: Proximity iOS app proposal, full Swift code scaffold, reference backend, testing docs, generated Xcode project

Proximity/Models/Connection.swift

@@ -0,0 +1,35 @@
+import Foundation
+
+/// A fully revealed, mutually-consented connection between two present users.
+///
+/// Connections can **only** be created from a mutual `Encounter`. There is no
+/// path to create one online — you must have been physically near each other.
+struct Connection: Identifiable, Codable, Hashable {
+    let id: UUID
+    let encounterID: UUID
+    let remoteUserID: String
+    let displayName: String
+    let createdAt: Date
+    let lastMessageAt: Date?
+
+    /// The E2E session key used for this conversation.
+    let sessionKeyID: String
+
+    init(
+        id: UUID = UUID(),
+        encounterID: UUID,
+        remoteUserID: String,
+        displayName: String,
+        createdAt: Date = Date(),
+        lastMessageAt: Date? = nil,
+        sessionKeyID: String
+    ) {
+        self.id = id
+        self.encounterID = encounterID
+        self.remoteUserID = remoteUserID
+        self.displayName = displayName
+        self.createdAt = createdAt
+        self.lastMessageAt = lastMessageAt
+        self.sessionKeyID = sessionKeyID
+    }
+}