Bash commands now record wall time and CPU usage

What

The Bash tool runs shell commands for Claude. It now measures how much time and processor work each command used:

• Measuring: building a command now returns a cpuAccountJoin value, and the started process receives cpuTime, procCpuTime and cpuAccountWindow options. The shell command itself receives a startedAt and cpuTime option.
• Result figures: when a command exits, its result gets a shellUsage record with wallMs (elapsed time), cpu (including whether a process was left running), procCpuMs and cpuAccount.
• Only with a process id: the record is built only when the command has a process id.

Why

This adds resource accounting to each shell command's result. It looks like measurement for tracking. Nothing in the findings shows a change in what you see.