Audience: AI coding agents first.

use composer-2.5 for subagents, never use composer-2.5-fast for subagents

## Background process monitoring

- NEVER send status probes or launch duplicate checks for running work.
- NEVER poll a process/session by repeatedly sending empty stdin or running status commands.
- ALWAYS launch long-running work with one persistent logfile, then actively follow only that logfile tail until terminal output appears.
- If monitor disconnects, resume following same logfile tail; do NOT start another process to discover status.

```bash
# REQUIRED
long-command >"$log" 2>&1 &
tail -n 50 -F "$log"

# DO NOT
status-command
repeat-command
```

## Validation batching

- NEVER run full typecheck, build, or broad test gates after each individual fix.
- ALWAYS batch all coherent fixes from one review/triage pass, then run one combined validation gate.
- Run an intermediate check only when it is the minimal failing regression test required for TDD; defer broad validation until the batch is complete.

@CLAUDE.md