[Bug] Session rename operation fails with ENOENT: no such file or directory

Bug Description
Renaming a session throws the following error:

This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason:
Error: ENOENT: no such file or directory, open 'n/a'
    at openSync (unknown)
    at <anonymous> (/$bunfs/root/claude:12:1277)
    at sW (/$bunfs/root/claude:11:8463)
    at appendFileSync (/$bunfs/root/claude:12:1200)
    at _g_ (/$bunfs/root/claude:1049:3119)
    at pGR (/$bunfs/root/claude:1050:78)
    at pGR (/$bunfs/root/claude:1050:214)
    at <anonymous> (/$bunfs/root/claude:3795:475)
    at <anonymous> (/$bunfs/root/claude:3795:527)
    at WT (/$bunfs/root/claude:4630:7)

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.0.76
• Feedback ID: f5902e3a-1050-41ec-8801-06d2f55e96a1

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/faizanali/.local/share/claude/versions/2.0.76 (expected in multi-process scenarios)\n    at XZR (/$bunfs/root/claude:2430:2165)\n    at fUA (/$bunfs/root/claude:2430:1885)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-06T18:31:45.627Z"}]