fix: reveal conversation actions on hover

Conversation rows always reserved space for the more-actions button, and the active row kept it visible. The button now replaces the right-side timestamp only on hover, keyboard focus, or while its menu is open, leaving more room for conversation titles and timestamps by default.

Release note: 会话列表仅在悬停或键盘聚焦时显示更多操作按钮，更新时间默认更靠右，为会话标题留出更多空间。

src/renderer/src/App.tsx

@@ -7640,13 +7640,7 @@ function App(): React.JSX.Element {
               `conversation-branch-disabled-${conversation.id}`
             return (
             <div className="conversation-entry" key={conversation.id}>
-              <div
-                className={
-                  conversation.id === activeId
-                    ? 'conversation-row conversation-row--active'
-                    : 'conversation-row'
-                }
-              >
+              <div className="conversation-row">
                 {conversationTasks.length > 0 && (
                   <button
                     aria-expanded={tasksExpanded}

src/renderer/src/WorkspacePrimitives.test.tsx

@@ -251,24 +251,33 @@ describe('WorkspacePrimitives', () => {
     )
   })
 
-  it('keeps the conversation action close to the sidebar edge', () => {
+  it('reveals the conversation action without reserving its space', () => {
     expect(stylesheet).toMatch(
       /\.conversation-row:has\(\.conversation-task-toggle\) \.conversation-item\s*\{[^}]*padding-left:\s*34px;/u
     )
     expect(stylesheet).toMatch(
       /\.conversation-task-toggle\s*\{[^}]*left:\s*3px;[^}]*width:\s*28px;[^}]*height:\s*28px;/u
     )
-    expect(stylesheet).toMatch(
-      /\.conversation-row \.conversation-item\s*\{[^}]*padding-right:\s*36px;/u
+    expect(stylesheet).not.toMatch(
+      /\.conversation-row \.conversation-item\s*\{[^}]*padding-right:/u
     )
     expect(stylesheet).toMatch(
       /\.conversation-more\s*\{[^}]*right:\s*5px;/u
     )
     expect(stylesheet).toMatch(
-      /\.conversation-row:has\(\.conversation-activity-indicator\)\s+\.conversation-item\s*\{[^}]*padding-right:\s*52px;/u
+      /\.conversation-row:hover \.conversation-more,\s*\.conversation-row:focus-within \.conversation-more,[^{]*\{[^}]*opacity:\s*1;/u
     )
     expect(stylesheet).toMatch(
-      /\.conversation-activity-indicator\s*\{[^}]*right:\s*38px;/u
+      /\.conversation-row:hover \.conversation-item small,[^{]*\.conversation-item small\s*\{[^}]*opacity:\s*0;/u
+    )
+    expect(stylesheet).not.toContain(
+      '.conversation-row--active .conversation-more'
+    )
+    expect(stylesheet).toMatch(
+      /\.conversation-row:has\(\.conversation-activity-indicator\)\s+\.conversation-item\s*\{[^}]*padding-right:\s*28px;/u
+    )
+    expect(stylesheet).toMatch(
+      /\.conversation-activity-indicator\s*\{[^}]*right:\s*10px;/u
     )
     expect(stylesheet).not.toContain('.conversation-delete')
   })

src/renderer/src/styles.css

@@ -2846,6 +2846,7 @@ textarea:focus-visible {
   flex: 0 0 auto;
   color: var(--text-muted);
   font-size: var(--font-caption);
+  transition: opacity var(--motion-fast) ease-out;
 }
 
 .overflow-marquee {
@@ -8900,18 +8901,14 @@ details.settings-section > :not(summary) + :not(summary) {
   align-items: center;
 }
 
-.conversation-row .conversation-item {
-  padding-right: 36px;
-}
-
 .conversation-row:has(.conversation-activity-indicator)
   .conversation-item {
-  padding-right: 52px;
+  padding-right: 28px;
 }
 
 .conversation-activity-indicator {
   position: absolute;
-  right: 38px;
+  right: 10px;
   width: 8px;
   height: 8px;
   border-radius: 50%;
@@ -8920,6 +8917,7 @@ details.settings-section > :not(summary) + :not(summary) {
   box-shadow: 0 0 0 4px
     color-mix(in srgb, var(--success) 14%, transparent);
   pointer-events: none;
+  transition: right var(--motion-fast) ease-out;
 }
 
 .conversation-more {
@@ -8940,11 +8938,25 @@ details.settings-section > :not(summary) + :not(summary) {
 }
 
 .conversation-row:hover .conversation-more,
-.conversation-row--active .conversation-more,
+.conversation-row:focus-within .conversation-more,
 .conversation-more:focus-visible {
   opacity: 1;
 }
 
+.conversation-row:hover .conversation-item small,
+.conversation-row:focus-within .conversation-item small,
+.conversation-row:has(.conversation-more[aria-expanded='true'])
+  .conversation-item small {
+  opacity: 0;
+}
+
+.conversation-row:hover .conversation-activity-indicator,
+.conversation-row:focus-within .conversation-activity-indicator,
+.conversation-row:has(.conversation-more[aria-expanded='true'])
+  .conversation-activity-indicator {
+  right: 38px;
+}
+
 .conversation-more[aria-expanded='true'] {
   background: var(--accent-subtle);
   color: var(--accent);