SessionStart hook sessionTitle is persisted but never shown in the TUI session-name badge

[BUG] SessionStart hook sessionTitle is persisted but never shown in the TUI session-name badge

Environment

• Claude Code v2.1.218 (also latest at time of writing)
• Windows 11, Git Bash (hook commands execute under bash)
• Interactive TUI session

Description

A SessionStart hook that returns hookSpecificOutput.sessionTitle runs successfully and the title is persisted — the session transcript receives a {"type":"custom-title","customTitle":"..."} record — but the session-name badge above the input box never displays it. The badge behaves as if the session were untitled for the entire session.

Setting a title interactively with /rename updates the badge immediately, so this appears to be a gap where the hook-driven title update reaches session persistence but not the TUI's in-memory display state.

Steps to reproduce

1. Create C:\projects\demo-app\.claude\settings.local.json (a trusted workspace):

{
  "hooks": {
    "SessionStart": [
      {
        "matcher": "startup",
        "hooks": [
          {
            "type": "command",
            "command": "echo '{\"hookSpecificOutput\":{\"hookEventName\":\"SessionStart\",\"sessionTitle\":\"Demo Session\"}}'"
          }
        ]
      }
    ]
  }
}

1. Run claude in C:\projects\demo-app and send any message.
2. Observe the session-name badge above the input box.

Expected

The badge shows "Demo Session", the same as if the user had run /rename Demo Session.

Actual

• The badge never appears / stays in its untitled state.
• The hook did run: its stdout is captured in the transcript with exit code 0, and the session .jsonl under ~/.claude/projects/<dir-slug>/ contains:

{"type":"custom-title","customTitle":"Demo Session","sessionId":"..."}

• The title is also persisted when the same hook is supplied via --settings <file> (verified in print mode), so the hook-output path itself works; only the badge display is missing.

Notes

• /rename from inside the session updates the badge instantly, so the display path exists — it's just not triggered by the hook's sessionTitle output.