#12 sync call history between devices via carbons and MAM

- After a call ends, send a plaintext <call-history/> service message
  to the user's own bare JID with direction, status, duration, start
  time, peer and video flag plus the call id as origin-id.
- Intercept the payload on live, carbon and MAM paths and upsert the
  same system call card on every device; deduplication reuses the
  origin-id as clientID, and missed incoming calls bump unread.
- Cover payload parsing and round-trip in CallHistorySyncTests, guard
  the namespace and interception in verify.sh, and document the flow
  in ARCHITECTURE.md.

Tests/CallHistorySyncTests.swift

@@ -0,0 +1,72 @@
+import Martin
+import XCTest
+@testable import Luma
+
+final class CallHistorySyncTests: XCTestCase {
+    private func makePayloadMessage(id: String = "call-42") -> Message {
+        let message = Message()
+        message.id = id
+        let payload = Element(name: "call-history", xmlns: CallHistorySync.namespace)
+        payload.addChild(Element(name: "direction", cdata: "incoming"))
+        payload.addChild(Element(name: "status", cdata: "missed"))
+        payload.addChild(Element(name: "duration", cdata: "0"))
+        payload.addChild(Element(name: "start", cdata: "2026-08-27T10:00:00Z"))
+        payload.addChild(Element(name: "with", cdata: "Bob@Example.org"))
+        payload.addChild(Element(name: "video", cdata: "false"))
+        message.addChild(payload)
+        return message
+    }
+
+    func testEnvelopeParsesPayload() throws {
+        let envelope = try XCTUnwrap(CallHistorySync.envelope(from: makePayloadMessage()))
+        XCTAssertEqual(envelope.id, "call-42")
+        XCTAssertEqual(envelope.peerJID, "bob@example.org")
+        XCTAssertEqual(envelope.direction, .incoming)
+        XCTAssertEqual(envelope.outcome, .missed)
+        XCTAssertFalse(envelope.isVideo)
+        XCTAssertNil(envelope.duration)
+        XCTAssertEqual(
+            envelope.startedAt,
+            ISO8601DateFormatter().date(from: "2026-08-27T10:00:00Z")
+        )
+    }
+
+    func testEnvelopePrefersOriginID() throws {
+        let message = makePayloadMessage()
+        let origin = Element(name: "origin-id", xmlns: "urn:xmpp:sid:0")
+        origin.setAttribute("id", value: "call-uuid")
+        message.addChild(origin)
+        XCTAssertEqual(CallHistorySync.envelope(from: message)?.id, "call-uuid")
+    }
+
+    func testEnvelopeIgnoresOrdinaryMessages() {
+        let message = Message()
+        message.body = "hello"
+        XCTAssertNil(CallHistorySync.envelope(from: message))
+    }
+
+    func testPayloadRoundTripPreservesCallDetails() throws {
+        let entry = CallHistoryEntry(
+            id: "call-1",
+            peerJID: "bob@example.org",
+            direction: .outgoing,
+            isVideo: true,
+            startedAt: Date(timeIntervalSince1970: 1_700_000_000),
+            endedAt: Date(timeIntervalSince1970: 1_700_000_042),
+            duration: 42,
+            outcome: .completed
+        )
+        let message = Message()
+        message.id = entry.id
+        message.addChild(CallHistorySync.payloadElement(entry: entry))
+
+        let envelope = try XCTUnwrap(CallHistorySync.envelope(from: message))
+        XCTAssertEqual(envelope.id, "call-1")
+        XCTAssertEqual(envelope.peerJID, "bob@example.org")
+        XCTAssertEqual(envelope.direction, .outgoing)
+        XCTAssertTrue(envelope.isVideo)
+        XCTAssertEqual(envelope.duration, 42)
+        XCTAssertEqual(envelope.outcome, .completed)
+    }
+}
+