[BUG] /resume shows only 5 of 130+ sessions - sessions-index.json mostly ignored

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

/resume in the CLI only displays 5 conversations despite 177 .jsonl session files on disk.

Ran the community repair script from #23614 to rebuild sessions-index.json — index now has 176 entries (up from 45). /resume still shows only the same 5 sessions. This confirms the CLI picker does NOT read sessions-index.json at all — it appears to scan .jsonl files by recency and hard-caps at ~5 results.

The VS Code extension shows significantly more sessions for the same project directory, including sessions originally started from the CLI that no longer appear in the CLI's own /resume picker.

What Should Happen?

All sessions should be discoverable in the /resume picker. CLI and VS Code extension should show the same sessions. A reindex command should exist to rebuild sessions-index.json from .jsonl files on disk. The picker should support pagination/scrolling, not cap at ~5 results.

Error Messages/Logs

$ ls ~/.claude/projects/C--Users-Dimi-repo/*.jsonl | wc -l
130+

$ cat ~/.claude/projects/C--Users-Dimi-repo/sessions-index.json | jq '.entries | length'
42

# But /resume only shows 5 sessions:
# Garmin Visuals (20h ago, 6.6 MB) — NOT in index
# permissions audit (21h ago, 2.0 MB) — NOT in index
# buggychat (23h ago, 3.3 KB) — NOT in index
# Humanizer (6 days ago, 654 KB) — in index with customTitle
# Marsol Zombie (1 week ago, 38.7 MB) — in index with customTitle

# 9 sessions have customTitle in index but only 2 appear in picker
# Case inconsistency in projectPath: "C:\Users\Dimi\repo" vs "c:\Users\Dimi\repo"

Steps to Reproduce

1. Use Claude Code v2.1.37 across CLI and VS Code extension over several weeks
2. Accumulate 100+ session .jsonl files in ~/.claude/projects/<project>/
3. Run /resume in CLI — only 5 sessions appear
4. Open VS Code extension session history — many more sessions visible, including ones started from CLI
5. Inspect sessions-index.json — only 42 of 130+ sessions indexed, 9 with customTitle, but only 2 shown

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.37 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Tested /resume from Git Bash, PowerShell, and Command Prompt — same result in all three, only 5 sessions shown. Rebuilt sessions-index.json using community repair script (45 → 176 entries) with zero effect on /resume output. Related: #23614 #23421