[BUG] Ctrl+O transcript view: past thinking blocks disappear, latest one appears at wrong position (2.1.x)

Summary

In Claude Code 2.1.x, the Ctrl+O transcript view no longer displays thinking blocks correctly:

1. Past turns' thinking blocks disappear entirely
2. Latest turn's thinking block appears at the very bottom, instead of immediately before its corresponding output

This worked correctly in 2.0.x, where thinking blocks appeared interleaved with outputs in chronological order.

Environment

• Claude Code version: 2.1.5
• Platform: Linux (VS Code DevContainer on macOS Apple Silicon host)
• Terminal: VS Code integrated terminal
• Model: claude-opus-4-5-20251101

Steps to Reproduce

1. Start a Claude Code session with thinking enabled (Opus 4.5 has it on by default)
2. Have a multi-turn conversation (3+ exchanges)
3. Press Ctrl+O to open transcript view
4. Scroll through the transcript

Expected Behavior (2.0.x)

● Tool call (Web Search)
  ⎿  Results...

∴ Thinking…
  [thinking content for the response below]

● Response A

❯ User message

∴ Thinking…
  [thinking content for the response below]

● Response B

Each thinking block appears immediately before its corresponding response, in chronological order.

Actual Behavior (2.1.x)

● Tool call (Web Search)
  ⎿  Results...

● Response A                          ← thinking block is MISSING

❯ User message

● Response B                          ← thinking block is MISSING

∴ Thinking…
  [only the LATEST thinking block, at the BOTTOM]

• Past turns' thinking blocks are gone
• The latest thinking block appears at the bottom of the transcript, not before its response

Why This Matters

Thinking blocks are essential for:

• Understanding Claude's reasoning process
• Debugging unexpected behavior
• Learning how the model approaches problems

Many users (especially developers working with AI) actively monitor thinking blocks to:

• Catch misunderstandings early
• Understand decision-making patterns
• Improve prompting strategies

The current behavior makes it impossible to review past reasoning within a session.

Related Issues

• #8371 — Request to restore pre-2.0.0 thinking display (different issue: inline display vs transcript)
• #9057 — Thinking transcript removed in v2.0.9 (partially addressed with Ctrl+O, but now broken again)

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✍️ Author: Claude Code (DevContainer) with @carrotRakko

Note: This issue was written and submitted by an AI agent (Claude Code), with human review and approval.