VSCode extension v2.1.101: session .jsonl files only contain ai-title, no conversation content

Description

After updating the VSCode extension to v2.1.101 (installed 2026-04-11), all new conversation sessions only persist the ai-title entry to the .jsonl file. No user, assistant, file-history-snapshot, or other message types are written. Previous sessions (created with v2.1.92 and earlier) have full conversation data.

Steps to reproduce

1. Update Claude Code VSCode extension to v2.1.101
2. Start a new conversation in VSCode
3. Have a multi-turn conversation with tool use
4. Close the conversation
5. Reopen it — title is visible but content is empty

Evidence

Session files in ~/.claude/projects/<project>/:

Old session (v2.1.92, working):

$ wc -l 076fa6e7-*.jsonl
120 076fa6e7-bfd9-4baa-8339-9c97c839a712.jsonl

$ python3 -c "..."  # types: file-history-snapshot, queue-operation, user, last-prompt, ai-title, assistant, attachment

New session (v2.1.101, broken):

$ cat 349d9334-*.jsonl
{"type":"ai-title","sessionId":"349d9334-19e4-477b-a628-c5f4d667046e","aiTitle":"Evidence-based learning system with agent design"}

All 6 sessions created on 2026-04-12 show the same pattern: 1 line, only ai-title, ~130 bytes. All sessions before 2026-04-11 have full content (50KB–6MB).

Environment

• macOS Darwin 25.4.0 (Apple Silicon)
• VSCode (latest)
• Extension versions installed:
• anthropic.claude-code-2.1.89-darwin-arm64 (Apr 1)
• anthropic.claude-code-2.1.92-darwin-arm64 (Apr 7)
• anthropic.claude-code-2.1.101-darwin-arm64 (Apr 11) ← broken
• ~/.claude/sessions/ directory is empty
• Custom hooks configured in settings.json (PreToolUse, PostToolUse, PostCompact, Stop) — but hooks don't interact with session persistence

Related

Possibly related to #46683 (2.1.101 /resume regression), though that issue is about cross-repo session visibility, not missing content.