make the reply swipe reliable and add a telegram-style plate

- Lock the gesture into a reply swipe once it starts clearly
  horizontal (1.6 dominance, 12pt) and relax the ratio to 1.05
  afterwards, so a slightly diagonal finish no longer cancels the
  swipe while vertical scrolls stay untouched.
- Restyle the composer reply banner as a rounded telegram-like card
  with the reply header, close button and two-line quote preview.
- Cover the lock/follow behaviour in MessageReplySwipeTests.

Tests/MessageReplySwipeTests.swift

@@ -5,10 +5,12 @@ import XCTest
 final class MessageReplySwipeTests: XCTestCase {
     func testHorizontalSwipeInEitherDirectionReplies() {
         XCTAssertTrue(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: 70, height: 8),
             predictedEndTranslation: CGSize(width: 72, height: 9)
         ))
         XCTAssertTrue(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: -70, height: 8),
             predictedEndTranslation: CGSize(width: -72, height: 9)
         ))
@@ -16,6 +18,7 @@ final class MessageReplySwipeTests: XCTestCase {
 
     func testVerticalTimelineScrollDoesNotReply() {
         XCTAssertFalse(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: 42, height: 80),
             predictedEndTranslation: CGSize(width: 50, height: 105)
         ))
@@ -23,17 +26,33 @@ final class MessageReplySwipeTests: XCTestCase {
 
     func testDiagonalTimelineScrollDoesNotReply() {
         XCTAssertFalse(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: 54, height: 44),
             predictedEndTranslation: CGSize(width: 76, height: 58)
         ))
         XCTAssertEqual(
-            MessageReplySwipePolicy.offset(for: CGSize(width: 54, height: 44)),
+            MessageReplySwipePolicy.offset(locked: false, translation: CGSize(width: 54, height: 44)),
+            0
+        )
+    }
+
+    func testDiagonalScrollAtOldThresholdDoesNotReply() {
+        // width/height ≈ 1.5 passed the old 1.4 dominance and moved bubbles
+        // during scrolling; the stricter policy must stay silent.
+        XCTAssertFalse(MessageReplySwipePolicy.shouldReply(
+            locked: false,
+            translation: CGSize(width: 60, height: 40),
+            predictedEndTranslation: CGSize(width: 60, height: 40)
+        ))
+        XCTAssertEqual(
+            MessageReplySwipePolicy.offset(locked: false, translation: CGSize(width: 60, height: 40)),
             0
         )
     }
 
     func testShortSwipeDoesNotReply() {
         XCTAssertFalse(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: 36, height: 4),
             predictedEndTranslation: CGSize(width: 48, height: 5)
         ))
@@ -41,39 +60,48 @@ final class MessageReplySwipeTests: XCTestCase {
 
     func testFastHorizontalFlickUsesPredictedEnd() {
         XCTAssertTrue(MessageReplySwipePolicy.shouldReply(
+            locked: false,
             translation: CGSize(width: -35, height: 3),
             predictedEndTranslation: CGSize(width: -90, height: 7)
         ))
     }
 
-    func testDiagonalScrollAtOldThresholdDoesNotReply() {
-        // width/height ≈ 1.5 passed the old 1.4 dominance and moved bubbles
-        // during scrolling; the stricter policy must stay silent.
-        XCTAssertFalse(MessageReplySwipePolicy.shouldReply(
-            translation: CGSize(width: 60, height: 40),
-            predictedEndTranslation: CGSize(width: 60, height: 40)
-        ))
-        XCTAssertEqual(
-            MessageReplySwipePolicy.offset(for: CGSize(width: 60, height: 40)),
-            0
-        )
-    }
-
     func testIndicatorStaysHiddenUntilActivationDistance() {
         XCTAssertEqual(
-            MessageReplySwipePolicy.offset(for: CGSize(width: 20, height: 0)),
+            MessageReplySwipePolicy.offset(locked: false, translation: CGSize(width: 20, height: 0)),
             0
         )
         XCTAssertGreaterThan(
-            MessageReplySwipePolicy.offset(for: CGSize(width: 24, height: 0)),
+            MessageReplySwipePolicy.offset(locked: false, translation: CGSize(width: 24, height: 0)),
             0
         )
     }
 
     func testVisualOffsetIsCapped() {
         XCTAssertEqual(
-            MessageReplySwipePolicy.offset(for: CGSize(width: 500, height: 0)),
+            MessageReplySwipePolicy.offset(locked: true, translation: CGSize(width: 500, height: 0)),
             MessageReplySwipePolicy.maximumOffset
         )
     }
+
+    func testCanLockRequiresClearHorizontalStart() {
+        XCTAssertTrue(MessageReplySwipePolicy.canLock(CGSize(width: 24, height: 10)))
+        XCTAssertFalse(MessageReplySwipePolicy.canLock(CGSize(width: 30, height: 20)))
+        XCTAssertFalse(MessageReplySwipePolicy.canLock(CGSize(width: 8, height: 5)))
+    }
+
+    func testLockedSwipeToleratesVerticalDrift() {
+        // Once locked the finger may drift: a 1.17 ratio would be rejected
+        // by the 1.6 lock dominance but must still count as a reply swipe.
+        XCTAssertTrue(MessageReplySwipePolicy.shouldReply(
+            locked: true,
+            translation: CGSize(width: 70, height: 60),
+            predictedEndTranslation: CGSize(width: 70, height: 60)
+        ))
+        XCTAssertGreaterThan(
+            MessageReplySwipePolicy.offset(locked: true, translation: CGSize(width: 70, height: 60)),
+            0
+        )
+    }
 }
+