[Bug] Claude Opus 4.5 ignores instructions, significant degradation since Jan 14

Bug Description
Since 14 January, there has been a significant degradation in the performance of Claude Opus 4.5. Specifically, Claude Code appears to disregard all provided instructions, whereas Claude Sonnet 4.5 continues to function effectively. I have recorded a screencast documenting these issues as evidence: https://share.cleanshot.com/kvvM1hDN

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.17
• Feedback ID: 2813710d-990a-4b94-9e4e-4838652b53f1

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at vW (/$bunfs/root/claude:11:35097)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at y2R (/$bunfs/root/claude:1479:380)\n    at y2R (/$bunfs/root/claude:1479:1350)\n    at <anonymous> (/$bunfs/root/claude:1479:4440)\n    at <anonymous> (/$bunfs/root/claude:1479:5171)\n    at A (/$bunfs/root/claude:11:7244)\n    at pX8 (/$bunfs/root/claude:4784:4342)","timestamp":"2026-01-23T11:08:00.720Z"}]