Slow Operation Detection

What: New performance monitoring that detects and logs slow filesystem and shell command operations.

How it works:

• All synchronous filesystem operations (20 in total) are now wrapped with timing instrumentation
• Shell command executions via execSyncWithDefaults are similarly monitored
• Operations exceeding 5ms are logged to debug output with the operation name and duration

Details:

• Log format: [SLOW OPERATION DETECTED] fs.readFileSync (12.3ms) or [SLOW OPERATION DETECTED] execSyncWithDefaults (156.7ms): git status...
• Monitored fs operations include: existsSync, statSync, readFileSync, writeFileSync, appendFileSync, copyFileSync, unlinkSync, renameSync, readdirSync, mkdirSync, rmdirSync, rmSync, and others
• For shell commands, the first 100 characters of the command are included in the log
• Logs are written to debug output (controlled by CLAUDE_CODE_DEBUG_LOGS_DIR environment variable)
• Evidence: XX() wrapper function at line 554, threshold Zl2 = 5 at line 605, shell monitoring in MG() at line 16934