AppRC 0.29.0

💥 Breaking changes

• Breaking: Removed the config purge CLI command. Applications and scripts
  using it must explicitly mount rc.cli.mount_appdata_cli(app, MyRC) and
  invoke appdata clean instead; no alias remains. Add paths and clean
  action prefixes to the application's existing runtime-independent policy.
  Use each action's --apprc-dir PATH for explicit cleanup targeting rather
  than root env-file or storage selectors. config paths remains configuration
  diagnostics; manager-level plan_purge() and apply_purge(plan) are unchanged.

• Breaking: Renamed the durable repository backlog from TODO.md to
  BACKLOG.md. Contributors and tooling using the old path must update their
  links; existing entries are preserved. Reserve TODO.md for active-pass
  checklists beside PLAN.md.

➕ Added

• Added an opt-in application-data CLI with appdata paths, a structured
  appdata paths --json cleanup inventory, and previewed, confirmed
  appdata clean removal. It uses the existing managed-file and internal-storage
  safety boundary without resolving application settings, retains external
  payloads and unrelated files, and is demonstrated by all executable examples.

🔨 Fixed

• Deferred release dependency locking until all three distribution versions are
  regenerated, so minor releases do not resolve mismatched workspace metadata.