fix(tui): render tool trail before anchored inline diffs

Inline diff segments were anchored relative to assistant narration, but the
turn details pane still rendered after streamSegments. On completion that put
the diff before the tool telemetry that produced it. When a turn has anchored
diff segments, commit the accumulated thinking/tool trail as a pre-diff trail
message, then render the diff and final summary.

ui-tui/src/app/turnController.ts

@@ -33,6 +33,12 @@ const diffSegmentBody = (msg: Msg): null | string => {
   return m ? m[1]! : null
 }
 
+const insertBeforeFirstDiff = (segments: Msg[], msg: Msg): Msg[] => {
+  const index = segments.findIndex(segment => segment.kind === 'diff')
+
+  return index < 0 ? [...segments, msg] : [...segments.slice(0, index), msg, ...segments.slice(index)]
+}
+
 export interface InterruptDeps {
   appendMessage: (msg: Msg) => void
   gw: { request: <T = unknown>(method: string, params?: Record<string, unknown>) => Promise<T> }
@@ -292,16 +298,30 @@ class TurnController {
       return body === null || (!finalHasOwnDiffFence && !finalText.includes(body))
     })
 
-    const finalMessages = [...segments]
+    const hasDiffSegment = segments.some(msg => msg.kind === 'diff')
+    const detailsBelongBeforeDiff = hasDiffSegment && (tools.length > 0 || Boolean(savedReasoning))
+    const finalMessages = detailsBelongBeforeDiff
+      ? insertBeforeFirstDiff(segments, {
+          kind: 'trail',
+          role: 'system',
+          text: '',
+          thinking: savedReasoning || undefined,
+          thinkingTokens: savedReasoning ? savedReasoningTokens : undefined,
+          toolTokens: savedToolTokens || undefined,
+          ...(tools.length && { tools })
+        })
+      : [...segments]
 
     if (finalText) {
       finalMessages.push({
         role: 'assistant',
         text: finalText,
-        thinking: savedReasoning || undefined,
-        thinkingTokens: savedReasoning ? savedReasoningTokens : undefined,
-        toolTokens: savedToolTokens || undefined,
-        ...(tools.length && { tools })
+        ...(!detailsBelongBeforeDiff && {
+          thinking: savedReasoning || undefined,
+          thinkingTokens: savedReasoning ? savedReasoningTokens : undefined,
+          toolTokens: savedToolTokens || undefined,
+          ...(tools.length && { tools })
+        })
       })
     }