Trying to add spacer at the end of the transcript

ios/Packages/Sybil/Tests/SybilTests/SybilTests.swift

@@ -784,3 +784,23 @@ private func makeSearchDetail(id: String, date: Date, answer: String) -> SearchD
     #expect(BackSwipeMetrics.shouldComplete(offset: 24, velocityX: 800, width: width, isLatched: false))
     #expect(!BackSwipeMetrics.shouldComplete(offset: latchDistance + 1, velocityX: -800, width: width, isLatched: true))
 }
+
+@Test func transcriptTailSpacerContractsAsContentGrows() async throws {
+    let targetHeight: CGFloat = 320
+    let baselineAssistantHeight: CGFloat = 28
+
+    #expect(
+        SybilTranscriptTailSpacer.placeholderHeight(
+            targetHeight: targetHeight,
+            baselineAssistantHeight: baselineAssistantHeight,
+            currentAssistantHeight: baselineAssistantHeight + 120
+        ) == 200
+    )
+    #expect(
+        SybilTranscriptTailSpacer.placeholderHeight(
+            targetHeight: targetHeight,
+            baselineAssistantHeight: baselineAssistantHeight,
+            currentAssistantHeight: baselineAssistantHeight + 500
+        ) == SybilTranscriptTailSpacer.minimumHeight
+    )
+}