Add consistent policy for what hook output to show vs suppress:
- EXPOSE: errors, warnings, debug statements, uncommitted work
- HIDE: format success, coverage stable, pass confirmations
New files:
- output-policy.sh: helper functions (expose_error, expose_warning, hide_success)
- hook-output-policy.md: documentation
Updated hooks to use proper Claude Code JSON output format:
- check-debug.sh: expose warnings via additionalContext
- post-commit-check.sh: expose uncommitted work warnings
- check-coverage.sh: expose coverage drops
- go-format.sh: suppress output on success
- php-format.sh: suppress output on success
Closes#17
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>