VSCode extension silently drops recent sessions from dropdown — files intact on disk

Environment

• Claude Code extension v2.1.63 (win32-x64)
• VSCode 1.106.3
• Windows 11 Pro 10.0.26200

Description

Sessions created within the last 24 hours disappear from the VSCode Claude Code session dropdown. The .jsonl files remain intact on disk with full content — the extension simply stops listing them.

Evidence

• Project session directory contains 90 .jsonl files
• Extension dropdown only shows ~65 of them
• Specific example: session 9993b9fa ("The shuffling animation makes it so you can't click or do anything") — 752KB, created March 5 2:27am — gone from dropdown by 8:30am the same day
• 25 out of 37 recent sessions (>100KB, last 3 days) are missing from the dropdown
• Confirmed the extension does NOT read sessions-index.json (0 references in extension.js) — it scans .jsonl files directly via readdir
• Files are not deleted, corrupted, or empty — they contain full conversation data

Reproduction

1. Open multiple Claude Code sessions over a few hours
2. Close some tabs, keep working in others
3. Check the session dropdown — recently closed sessions vanish
4. Verify files still exist: ls ~/.claude/projects/<project-dir>/*.jsonl

Additional context

Previously reported a related issue: clicking an existing session tab causes it to go blank — tab title reverts to "Claude Code" and content is lost from the dropdown, though the .jsonl file remains on disk.

This appears to be either an in-memory cache that doesn't persist/reload properly, or an internal cap on how many sessions the dropdown tracks.