Got fed up and built something for it. Myrlin scans ~/.claude/projects/, finds all your sessions, and you organize them into workspaces. You can drag sessions into a 4-pane terminal grid (real node-pty, not fake terminals), see costs, search through session history, keep notes per workspace. Runs in the browser, everything stays local.
Node.js + Express, vanilla JS, xterm.js for terminals, SSE for live updates. No build step. Went with Node because node-pty works on Windows without needing WSL or tmux.
You can try it without touching your real sessions:
git clone https://github.com/therealarthur/myrlin-workbook.git
cd myrlin-workbook && npm install && npm run gui:demo
AGPL-3.0. The whole thing was built in Claude Code sessions managed by Myrlin itself which was kind of fun. Would love to hear what's missing or broken.