Chat New line: skip the bubble pull-up when no hover row draws; trim above a leading turn bar

From review: the -mt-6 assumed the user bubble's copy/time row is drawn,
but a message with no timestamp may draw none, and the line would then
reach into the bubble. It now requires a timestamp. An above-row line
followed by its row's own turn bar (a turn opened without a prompt) gets
the same deeper trim as above-turn-bar.

Co-Authored-By: Claude <noreply@anthropic.com>

src/renderer/src/components/native-chat/messages/rows/NativeChatTranscriptRow.new-rows-spacing.test.tsx

@@ -27,7 +27,6 @@ const context: NativeChatTranscriptRowContext = {
   taskListPredecessors: new Map(),
   expandedTurnIds: new Set(),
   onToggleExpandedTurn: vi.fn(),
-  subagentDisclosure: { setSectionOpen: vi.fn(), setRosterOpen: vi.fn() },
   onScrollMessageToTop: vi.fn(),
   onRevealDiff: vi.fn()
 }
@@ -51,8 +50,6 @@ function slot(overrides: Partial<NativeChatMessageSlot> = {}): NativeChatMessage
     drawsMessage: true,
     turnFolds: false,
     turnDiff: undefined,
-    subagentRoster: undefined,
-    depth: 0,
     estimatedHeight: 40,
     ...overrides
   }
@@ -127,7 +124,17 @@ describe('NativeChatTranscriptRow New line spacing', () => {
       ['-mb-3'],
       ['-mt-6']
     ],
-    ['above-turn-bar', user(), { text: 'Not sent' }, ['-mb-3'], ['-mt-6']]
+    ['above-turn-bar', user(), { text: 'Not sent' }, ['-mb-3'], ['-mt-6']],
+    ['above-turn-bar', user(), { sending: true }, ['-mb-3'], ['-mt-6']],
+    ['above-turn-bar', user({ timestamp: null }), undefined, ['-mb-3'], ['-mt-6']],
+    ['above-turn-bar', { ...user(), drawsMessage: false }, undefined, ['-mb-3'], ['-mt-6']],
+    [
+      'above-row',
+      slot({ statusAbove: true, status: { startedAt: 1, thinking: false, workedSeconds: null } }),
+      undefined,
+      ['-mb-3'],
+      ['-mt-6', '-mb-1.5']
+    ]
   ] as const)('spaces the line %s, case %#', (place, row, notice, has, lacks) => {
     const view = render(
       <NativeChatTranscriptRow

src/renderer/src/components/native-chat/messages/rows/NativeChatTranscriptRow.tsx

@@ -58,14 +58,17 @@ function newRowsMarkerSpacing(
   deliveryNotice: NativeChatDeliveryNotice | undefined
 ): string {
   if (place === 'above-row') {
-    return '-mb-1.5'
+    // A turn with no prompt opens on its bar, which needs the deeper trim too.
+    return slot.statusAbove && slot.status ? '-mb-3' : '-mb-1.5'
   }
+  // Only where the hover row is drawn: it always shows a time, so a message without one may have none.
   const afterHoverMeta =
     slot.drawsMessage &&
     !slot.receipt &&
     slot.message.role === 'user' &&
     !slot.message.from &&
-    deliveryNotice === undefined
+    deliveryNotice === undefined &&
+    Number.isFinite(slot.message.timestamp)
   return cn('-mb-3', afterHoverMeta && '-mt-6')
 }