Polish message row hover states (#880)

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

@@ -6,7 +6,7 @@ export function DayDivider({ label }: { label: string }) {
       data-testid="message-timeline-day-divider"
       data-day-label={label}
     >
-      <p className="shrink-0 rounded-full bg-background/90 px-2 py-0.5 text-[10px] font-medium tracking-[0.02em] text-muted-foreground/65 backdrop-blur-sm">
+      <p className="shrink-0 rounded-lg border border-border/70 bg-background/95 px-2 py-1 text-[10px] font-medium tracking-[0.02em] text-muted-foreground/70 shadow-xs backdrop-blur-sm">
         {label}
       </p>
     </section>

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

@@ -30,6 +30,7 @@ export const MessageRow = React.memo(
   function MessageRow({
     channelId = null,
     highlighted = false,
+    hoverBackground = true,
     isFollowingThread,
     layoutVariant = "default",
     message,
@@ -45,6 +46,7 @@ export const MessageRow = React.memo(
   }: {
     channelId?: string | null;
     highlighted?: boolean;
+    hoverBackground?: boolean;
     isFollowingThread?: boolean;
     layoutVariant?: "default" | "thread-reply";
     message: TimelineMessage;
@@ -314,7 +316,8 @@ export const MessageRow = React.memo(
 
         <article
           className={cn(
-            "group/message relative rounded-2xl px-2 py-1 transition-colors",
+            "group/message relative rounded-2xl px-3 py-2 transition-colors",
+            hoverBackground && "hover:bg-muted/50 focus-within:bg-muted/50",
             "flex items-start gap-2.5",
             highlighted
               ? "-mx-4 rounded-none px-6 before:absolute before:-inset-y-1.5 before:inset-x-0 before:animate-[route-target-highlight-fade_2s_ease-out_forwards] before:bg-primary/10 before:content-[''] motion-reduce:before:animate-none sm:-mx-6 sm:px-8"
@@ -448,6 +451,7 @@ export const MessageRow = React.memo(
     prev.message.role === next.message.role &&
     prev.message.personaDisplayName === next.message.personaDisplayName &&
     prev.highlighted === next.highlighted &&
+    prev.hoverBackground === next.hoverBackground &&
     prev.isFollowingThread === next.isFollowingThread &&
     prev.layoutVariant === next.layoutVariant &&
     prev.profiles === next.profiles &&

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

@@ -309,11 +309,16 @@ export function MessageThreadPanel({
                   {threadReplies.map((entry) => {
                     return (
                       <div
-                        className="flex flex-col gap-1"
+                        className={cn(
+                          "flex flex-col gap-1",
+                          entry.summary &&
+                            "group/message -mx-1 rounded-2xl px-1 py-1 transition-colors hover:bg-muted/50 focus-within:bg-muted/50",
+                        )}
                         key={entry.message.id}
                       >
                         <MessageRow
                           channelId={channelId}
+                          hoverBackground={!entry.summary}
                           layoutVariant="thread-reply"
                           message={entry.message}
                           onDelete={

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

@@ -321,7 +321,7 @@ export const SystemMessageRow = React.memo(function SystemMessageRow({
 
   return (
     <div
-      className="group/message relative rounded-2xl px-2 py-1 transition-colors"
+      className="group/message relative rounded-2xl px-3 py-2 transition-colors hover:bg-muted/50 focus-within:bg-muted/50"
       data-testid="system-message-row"
     >
       <div className="flex items-start gap-2.5">

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

@@ -108,7 +108,7 @@ export const TimelineMessageList = React.memo(function TimelineMessageList({
         <div
           key={message.id}
           className={cn(
-            "relative flex flex-col gap-0",
+            "group/message relative -mx-1 flex flex-col gap-0 rounded-2xl px-1 py-1 transition-colors hover:bg-muted/50 focus-within:bg-muted/50",
             isHighlighted &&
               "-mx-4 px-4 before:absolute before:-inset-y-1.5 before:inset-x-0 before:animate-[route-target-highlight-fade_2s_ease-out_forwards] before:bg-primary/10 before:content-[''] motion-reduce:before:animate-none sm:-mx-6 sm:px-6",
           )}
@@ -116,6 +116,7 @@ export const TimelineMessageList = React.memo(function TimelineMessageList({
           <MessageRow
             channelId={channelId}
             highlighted={false}
+            hoverBackground={false}
             isFollowingThread={
               isFollowingThreadById
                 ? isFollowingThreadById(message.id)

desktop/tests/e2e/messaging.spec.ts

@@ -403,6 +403,7 @@ test("opens a single-level thread panel with inline expansion", async ({
   const siblingReply = `Sibling threaded reply ${timestamp}`;
   const nestedReply = `Nested threaded reply ${timestamp}`;
   const nestedReplyFromBob = `Nested reply from Bob ${timestamp}`;
+  const nestedReplyVisibleTopMaxPx = 260;
   const fillerReplies = Array.from(
     { length: 14 },
     (_, index) => `Thread filler reply ${index} ${timestamp}`,
@@ -524,7 +525,7 @@ test("opens a single-level thread panel with inline expansion", async ({
         return rowRect.top - bodyRect.top;
       });
     })
-    .toBeLessThanOrEqual(240);
+    .toBeLessThanOrEqual(nestedReplyVisibleTopMaxPx);
 
   const firstReplyId = await firstReplyRow.getAttribute("data-message-id");
   if (!firstReplyId) {
@@ -578,7 +579,7 @@ test("opens a single-level thread panel with inline expansion", async ({
         return rowRect.top - bodyRect.top;
       });
     })
-    .toBeLessThanOrEqual(240);
+    .toBeLessThanOrEqual(nestedReplyVisibleTopMaxPx);
 
   await firstReplySummaryRow.click();
   await expect(