v0.13.0

Added

• Recursive subcommand capture: init walks nested subcommands (git remote add)
  and renders them as indented ### Subcommands bullets; verify recursively
  drift-checks every documented subcommand path.
• Structured logging: --log-level (off/error/warn/info/debug/trace) and
  --log-format (human/json) route spawn calls and introspection traces through
  tracing; --debug is now an alias for --log-level debug.

Changed

• ProjectProfile.cli_subcommand_help is replaced by the recursive
  cli_subcommand_tree: Vec<SubcommandNode> (breaking for library and
  doctor --format json consumers).
• VerifyInput.debug / InvocationInput.debug removed; spawn logging now flows
  through the structured logger (breaking for library consumers).
• verify::invocation::extract_documented_subcommands returns Vec<Vec<String>>
  subcommand paths instead of Vec<String> (breaking for library consumers).