Release v0.1.2

Added

• --help / -h flag on all subcommands (archive, create, diff, emit, history, import, init, list, pin, unpin, render, schema, show, stats, sync, tree, update, validate)
• --description flag for cn create and cn update
• description field on the Prompt type
• cn show displays description when present
• README with full CLI reference, composition model docs, and development guide

Fixed

• All remaining process.exit() calls replaced with ExitError (prevents error duplication in lock-guarded blocks)
• cn import now splits on ## headings by default (--no-split to disable, replacing --split)
• Unused import cleanup (dedupById in diff.ts, Section in update.ts, errorOut in list.ts, join in sync.ts)
• Import statement ordering to satisfy Biome linter

Changed

• @biomejs/biome upgraded from 1.9.4 to 2.4.4
• biome.json updated for v2 configuration format