Tighten continuation message rows

desktop/src/features/messages/lib/rowHeightEstimate.test.mjs

@@ -23,6 +23,13 @@ test("estimateRowHeight: short text is near the floor", () => {
   assert.ok(h >= 60 && h < 120, `expected small, got ${h}`);
 });
 
+test("estimateRowHeight: continuation reserves its uniform padding", () => {
+  const h = estimateRowHeight(msg({ body: "hello" }), {
+    isContinuation: true,
+  });
+  assert.equal(h, 28);
+});
+
 test("estimateRowHeight: many lines reserve more", () => {
   const tall = estimateRowHeight(
     msg({ body: Array.from({ length: 20 }, (_, i) => `line ${i}`).join("\n") }),

desktop/src/features/messages/lib/rowHeightEstimate.ts

@@ -26,13 +26,13 @@ const TEXT_LINE_HEIGHT = 20;
 const CODE_LINE_HEIGHT = 19;
 const CHARS_PER_LINE = 64; // rough wrap width at the timeline column
 const ROW_CHROME = 26; // author/time header + denser row padding
-const CONTINUATION_ROW_CHROME = 8; // dense row padding only; header/avatar are hidden
+const CONTINUATION_ROW_CHROME = 8; // uniform py-1 padding; header/avatar are hidden
 const MEDIA_BLOCK_MARGIN_TOP = 4; // image/video blocks use mt-1 in markdown
 const REACTION_ROW = 24;
 const PREVIEW_CARD = 70;
 const MESSAGE_ITEM_BOTTOM_PADDING = 10; // TimelineMessageList pb-2.5
 const MIN_ESTIMATE = 60; // never reserve less than the old flat floor
-const CONTINUATION_MIN_ESTIMATE = 34;
+const CONTINUATION_MIN_ESTIMATE = 28;
 
 function mediaHeightFromDim(dim: string | undefined): number {
   const dimensions = dimensionsFromDim(dim);

desktop/src/features/messages/ui/MessageRow.tsx

@@ -420,8 +420,8 @@ export const MessageRow = React.memo(
       <div
         aria-hidden="true"
         className={cn(
-          "flex w-9 shrink-0 items-start justify-end pt-0.5",
-          isThreadReplyLayout ? "min-h-9 self-start" : "self-stretch",
+          "flex w-9 shrink-0 justify-end items-start pt-0.5",
+          isThreadReplyLayout ? "self-start" : "self-stretch",
         )}
       >
         <MessageTimestamp
@@ -472,7 +472,9 @@ export const MessageRow = React.memo(
         className={cn(
           "absolute right-2 top-1 z-10 sm:pointer-events-none",
           actionBarPlacement === "floating"
-            ? "sm:top-0 sm:-translate-y-1/2"
+            ? isContinuation
+              ? "sm:-top-3 sm:-translate-y-1/2"
+              : "sm:top-0 sm:-translate-y-1/2"
             : "sm:top-1 sm:translate-y-0",
         )}
       >

desktop/tests/e2e/messaging.spec.ts

@@ -734,7 +734,9 @@ test("opens a single-level thread panel with inline expansion", async ({
         return body.scrollHeight - body.clientHeight;
       });
     })
-    .toBeGreaterThanOrEqual(160);
+    // Compact continuation rows intentionally reduce the available overflow;
+    // this test only needs enough space to prove the thread body scrolls.
+    .toBeGreaterThan(0);
 
   await expect(
     timeline.getByTestId("message-row").filter({ hasText: firstReply }),