fix(tui): preserve completed thinking panel

ui-tui/src/__tests__/createGatewayEventHandler.test.ts

@@ -82,13 +82,12 @@ describe('createGatewayEventHandler', () => {
       type: 'message.complete'
     } as any)
 
-    expect(appended).toHaveLength(3)
+    expect(appended).toHaveLength(2)
     expect(appended[0]).toMatchObject({ kind: 'trail', role: 'system', text: '', thinking: 'mapped the page' })
-    expect(appended[1]).toMatchObject({ kind: 'trail', role: 'system', text: '' })
-    expect(appended[1]?.tools).toHaveLength(1)
-    expect(appended[1]?.tools?.[0]).toContain('hero cards')
-    expect(appended[1]?.toolTokens).toBeGreaterThan(0)
-    expect(appended[2]).toMatchObject({ role: 'assistant', text: 'final answer' })
+    expect(appended[0]?.tools).toHaveLength(1)
+    expect(appended[0]?.tools?.[0]).toContain('hero cards')
+    expect(appended[0]?.toolTokens).toBeGreaterThan(0)
+    expect(appended[1]).toMatchObject({ role: 'assistant', text: 'final answer' })
   })
 
   it('keeps tool tokens across handler recreation mid-turn', () => {
@@ -116,10 +115,10 @@ describe('createGatewayEventHandler', () => {
       type: 'message.complete'
     } as any)
 
-    expect(appended).toHaveLength(3)
-    expect(appended[1]?.tools).toHaveLength(1)
-    expect(appended[1]?.toolTokens).toBeGreaterThan(0)
-    expect(appended[2]).toMatchObject({ role: 'assistant', text: 'final answer' })
+    expect(appended).toHaveLength(2)
+    expect(appended[0]?.tools).toHaveLength(1)
+    expect(appended[0]?.toolTokens).toBeGreaterThan(0)
+    expect(appended[1]).toMatchObject({ role: 'assistant', text: 'final answer' })
   })
 
   it('streams legacy thinking.delta into visible reasoning state', () => {
@@ -136,6 +135,21 @@ describe('createGatewayEventHandler', () => {
     vi.useRealTimers()
   })
 
+  it('preserves streamed reasoning as one completed thinking panel after segment flushes', () => {
+    const appended: Msg[] = []
+    const streamed = 'first reasoning chunk\nsecond reasoning chunk'
+
+    const onEvent = createGatewayEventHandler(buildCtx(appended))
+
+    onEvent({ payload: { text: streamed }, type: 'reasoning.delta' } as any)
+    onEvent({ payload: { text: 'Before edit.' }, type: 'message.delta' } as any)
+    turnController.flushStreamingSegment()
+    onEvent({ payload: { text: 'final answer' }, type: 'message.complete' } as any)
+
+    expect(appended.map(msg => msg.thinking).filter(Boolean)).toEqual([streamed])
+    expect(appended[appended.length - 1]).toMatchObject({ role: 'assistant', text: 'final answer' })
+  })
+
   it('ignores fallback reasoning.available when streamed reasoning already exists', () => {
     const appended: Msg[] = []
     const streamed = 'short streamed reasoning'

ui-tui/src/app/turnController.ts

@@ -81,7 +81,6 @@ class TurnController {
   persistSpawnTree?: (subagents: SubagentProgress[], sessionId: null | string) => Promise<void>
   protocolWarned = false
   reasoningText = ''
-  reasoningSegmentOffset = 0
   segmentMessages: Msg[] = []
   pendingSegmentTools: string[] = []
   statusTimer: Timer = null
@@ -107,7 +106,6 @@ class TurnController {
   clearReasoning() {
     this.reasoningTimer = clear(this.reasoningTimer)
     this.reasoningText = ''
-    this.reasoningSegmentOffset = 0
     this.toolTokenAcc = 0
     patchTurnState({ reasoning: '', reasoningTokens: 0, toolTokens: 0 })
   }
@@ -202,15 +200,10 @@ class TurnController {
       patchTurnState({ reasoning: this.reasoningText, reasoningTokens: estimateTokensRough(this.reasoningText) })
     }
 
-    const thinking = this.reasoningText.slice(this.reasoningSegmentOffset).trim()
     const msg: Msg = {
       role: split.text ? 'assistant' : 'system',
       text: split.text,
       ...(!split.text && { kind: 'trail' as const }),
-      ...(thinking && {
-        thinking,
-        thinkingTokens: estimateTokensRough(thinking)
-      }),
       ...(this.pendingSegmentTools.length && { tools: this.pendingSegmentTools })
     }
 
@@ -220,7 +213,6 @@ class TurnController {
       this.segmentMessages = [...this.segmentMessages, msg]
     }
 
-    this.reasoningSegmentOffset = this.reasoningText.length
     this.pendingSegmentTools = []
     this.bufRef = ''
     patchTurnState({ streamPendingTools: [], streamSegments: this.segmentMessages, streaming: '' })
@@ -329,7 +321,7 @@ class TurnController {
       return body === null || (!finalHasOwnDiffFence && !finalText.includes(body))
     })
 
-    const finalThinking = savedReasoning.slice(this.reasoningSegmentOffset).trim()
+    const finalThinking = savedReasoning.trim()
     const finalDetails: Msg = {
       kind: 'trail',
       role: 'system',

ui-tui/src/components/thinking.tsx

@@ -646,22 +646,22 @@ export const Thinking = memo(function Thinking({
         {preview ? (
           mode === 'full' ? (
             lines.map((line, index) => (
-              <Text color={t.color.dim} dim key={index} wrap="wrap-trim">
+              <Text color={t.color.cornsilk} key={index} wrap="wrap-trim">
                 {line || ' '}
                 {index === lines.length - 1 ? (
-                  <StreamCursor color={t.color.dim} dimColor streaming={streaming} visible={active} />
+                  <StreamCursor color={t.color.cornsilk} streaming={streaming} visible={active} />
                 ) : null}
               </Text>
             ))
           ) : (
-            <Text color={t.color.dim} dim wrap="truncate-end">
+            <Text color={t.color.cornsilk} wrap="truncate-end">
               {preview}
-              <StreamCursor color={t.color.dim} dimColor streaming={streaming} visible={active} />
+              <StreamCursor color={t.color.cornsilk} streaming={streaming} visible={active} />
             </Text>
           )
         ) : (
-          <Text color={t.color.dim} dim>
-            <StreamCursor color={t.color.dim} dimColor streaming={streaming} visible={active} />
+          <Text color={t.color.cornsilk}>
+            <StreamCursor color={t.color.cornsilk} streaming={streaming} visible={active} />
           </Text>
         )}
       </Box>