VSCode: Sessions disappear from sidebar — mtime-based listing drops older sessions

Bug

Claude Code sessions disappear from the VSCode sidebar immediately — sessions created earlier the same day are never visible in the list. They exist on disk as .jsonl files with full valid content, but the UI never shows them. Search within the session list also doesn't find them.

Steps to Reproduce

1. Create several Claude Code sessions throughout the day
2. Open the sessions list in the sidebar
3. Sessions from earlier today are missing — they were never visible, not even briefly
4. The .jsonl files are present in ~/.claude/projects/<hash>/ with full content

Root Cause (from reverse-engineering extension.js v2.1.72)

The session listing pipeline works as follows:

1. Vj() scans the project directory for *.jsonl files using vscode.workspace.fs.readDirectory()
2. Qs() reads the first 64KB (KN = 65536) and last 64KB of each file to extract metadata (first prompt, last prompt, timestamps)
3. ns() extracts firstPrompt from the head buffer
4. UN() extracts lastPrompt from the tail buffer
5. Sessions are sorted by file mtime

The UI filters sessions with: sessions.value.filter((J) => J.messages.value.length > 0 || J.isOffline() || J.isLoading.value || J.isExplicit.value)

The problem appears to be that sessions with older mtime values are either:

• Not loaded at all (some kind of limit/pagination that isn't visible in the minified source)
• Filtered out by a condition that effectively caps how many sessions are shown

Evidence

• Sessions from earlier the same day are never visible — not even once
• Sessions from 2 days ago are somehow visible, while today's sessions are not
• The .jsonl files exist, are non-empty, and contain valid data
• touch-ing the .jsonl file does NOT reliably make the session reappear
• Developer: Reload Window may bring a session back, but not consistently
• sessions-index.json is not used by the extension — it scans .jsonl files directly. Populating the index with entries actually caused a separate bug.

No Known Workaround

There is no reliable way to bring back disappeared sessions. touch on the file, reloading the window — none work consistently.

Expected Behavior

All sessions should remain visible in the sidebar (or at minimum be findable via search), regardless of age. If pagination is needed for performance, there should be a "load more" or "show all" option.

Environment

• Claude Code extension v2.1.72
• VSCode (remote SSH to TrueNAS/Debian 12)
• ~100+ session files in the project directory
• Linux x64