[Feature Request] Add conversation compaction command similar to /btw for maintaining context

Bug Description
"why can't you compact conversation like /btw, make it side kick, instead of mainstream" helps continue the train of thought for the user"/

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.140
• Feedback ID: d8de6407-ce62-4e8d-b873-ea89201f0d0b

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/spartan_studio_master/.local/share/claude/versions/2.1.140 (expected in multi-process scenarios)\n    at g16 (/$bunfs/root/src/entrypoints/cli.js:2672:2257)\n    at RLH (/$bunfs/root/src/entrypoints/cli.js:2672:1337)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-13T01:58:13.402Z"},{"error":"Error: pdftoppm is not installed. Install poppler-utils (e.g. `brew install poppler` or `apt-get install poppler-utils`) to enable PDF page rendering.\n    at Ya7 (/$bunfs/root/src/entrypoints/cli.js:4923:916)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-13T03:30:19.070Z"},{"error":"AxiosError: timeout of 60000ms exceeded\n    at <anonymous> (/$bunfs/root/src/entrypoints/cli.js:121:13313)\n    at emit (node:events:92:22)\n    at <anonymous> (node:_http_client:474:83)\n    at request (/$bunfs/root/src/entrypoints/cli.js:123:2467)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-13T03:31:36.098Z"}]