Multi-session VS Code workflow is fundamentally broken — please dogfood this

Meta Report — Critical UX Failure

Summary

The multi-session VS Code workflow — running 4-5 Claude panels simultaneously on different tasks — is fundamentally broken. A real user lost an entire working day (Feb 12, 2026) to session management issues instead of doing actual work. Four separate bugs were filed today, but they all stem from the same root cause: nobody at Anthropic is using Claude Code the way power users do.

Please dogfood this exact workflow:

1. Open VS Code with a large monorepo
2. Open 4 Claude panels, each working on a different task
3. Have all 4 editing files simultaneously
4. Try to keep track of which session is which
5. Try to figure out which diff preview belongs to which session
6. Accidentally click the split panel button once
7. Watch everything fall apart

What the user experienced today (timeline):

1. Started with 4 active sessions
2. Sessions started splitting and swapping between panels (#25295)
3. Root cause: split panel button silently duplicates sessions (#25299)
4. 3 zombie processes attached to one session file
5. One session died from "Prompt is too long" — caused by edit tool storing full file content in session JSONL (#25274)
6. Diff preview windows popping up in random editor groups with no labels (#25300)
7. User spent 3+ hours on session management instead of coding
8. 10+ crashes of the same work stream, requiring manual handoff documents each time
9. User literally cannot tell which Claude panel is connected to which session

The bugs filed today:

• #25274 — Edit tool embeds full file content in toolUseResult.originalFile, silently bloating sessions until they crash
• #25295 — Sessions spontaneously split and swap between panels
• #25299 — Split panel button silently duplicates sessions with no warning
• #25300 — Diff preview windows are unlabeled and appear in random editor groups

What's needed:

1. Session identity — Every panel and every popup must show which session it belongs to
2. No silent duplication — The split button should either be removed or require confirmation
3. No hidden bloat — Tool results should not store full file contents
4. Diff windows must be tied to their source panel — or be disableable independently
5. Dogfood the multi-session workflow — This is how power users work. If it doesn't work with 4 panels, it doesn't work.

User quote:

"I have wasted two more hours today just trying to start working" "Claude Code has become UNUSABLE" "I have claudes all working in each others documents and streams its all screwing up"

Environment

• Claude Code v2.1.39 (VS Code extension, macOS)
• macOS Darwin 25.2.0
• User running 4-5 simultaneous Claude sessions daily