v0.1.0

First release. One rule file, enforced in Claude Code and in Codex CLI through
each harness's own hook mechanism.

Added

• Rules as markdown files: the matcher in the frontmatter, the message the agent
  reads in the body.
• Three tiers, most specific first: project-personal .handrail/local/,
  project-shared .handrail/, and global ~/.config/handrail/. A rule replaces
  a lower one of the same filename outright, and a stub carrying
  enabled: false switches an inherited rule off.
• handrail check validates every tier and prints the effective ruleset,
  annotated with tier, shadowing, and disabling.
• handrail test <event> dry-runs one synthetic event against the rules and
  exits 2 when the outcome is block.
• handrail sync writes handrail's hook entries into every detected harness.
  Where a harness cannot do what a rule asks, it substitutes the strongest
  action that harness supports and reports the substitution rather than
  degrading the rule silently.
• handrail advise reports which rules also translate into a native harness
  entry, such as a Claude Code permission deny.
• handrail trust grants a repo's committed .handrail/ rules permission to
  take effect.
• handrail import hookify converts hookify rule files into personal rules and
  reports anything the format cannot express.
• handrail doctor diagnoses the install offline.
• handrail version prints the version, commit, and build date.
• handrail hook is the entry point the harnesses call. Sync installs it.
• Plugins for Claude Code and Codex CLI from the repo's own marketplace,
  carrying the add skill. The plugin downloads the pinned binary on the next
  session start, verifies its checksum, and syncs once.
• Prebuilt binaries for macOS and Linux on amd64 and arm64, and a Homebrew cask
  at svyatov/tap/handrail. There is no Windows build.