[BUG] Session resume still doesn't display previous conversation messages (regression from #8937)

Summary

This is a continuation of #8937 which was auto-closed by a bot despite not being fixed. When resuming a session, previous conversation messages are not displayed - only collapsed tool outputs are shown.

Environment

• Claude Code version: 2.1.14
• OS: macOS (Darwin 25.2.0)
• Terminal: Standard terminal

Current Behavior

1. Start a session and have a conversation with multiple tool executions
2. Close the session
3. Resume with claude --resume <session-id>

What happens:

• Previous user messages and Claude responses are NOT shown
• Only tool outputs are displayed (collapsed, need Ctrl+O to expand)
• When sending a new message, old tool outputs appear AFTER the new message, breaking conversation flow

Example output after resume:

❯ claude --resume abc123

⏺ Bash(git show be2dd861...)
  ⎿  commit be2dd861...
     ... +11 lines (ctrl+o to expand)

⏺ Read(e2e-tests/README.md)
  ⎿  Read 280 lines

❯ hi

⏺ Hi! How can I help you?

⏺ Bash(git show be2dd861...)    <-- Old tool outputs appear again after new message
  ⎿  ...

⏺ Read(...)
  ⎿  ...

Expected Behavior

• Full conversation history should be displayed on resume (user messages + Claude responses)
• Session should resume in the same visual state as when closed
• New messages should appear after previous conversation, not interspersed with old tool outputs

Steps to Reproduce

1. Start a new session: claude
2. Have a conversation with multiple tool calls (e.g., ask Claude to read files, run git commands)
3. Note the session ID or use /rename to name it
4. Close the session (Ctrl+C or /exit)
5. Resume the session: claude --resume <session-id>
6. Observe that only tool outputs are shown, not the conversation
7. Send a new message (e.g., "hi")
8. Observe that old tool outputs appear after the new message

Impact

• Hard to understand context when resuming a session
• Confusing conversation flow when old tool outputs appear after new messages
• Users have to scroll up or use Ctrl+O repeatedly to piece together what happened
• Makes session resume feature less useful for long-running or complex tasks

Related Issues

• #8937 - Original report (incorrectly auto-closed by bot)
• #12774 - Session Continuity Improvements (open enhancement request)