refactor: extract shared dry-run, config-persist, and command helpers (v0.4.4)

[masonlet]

Summary

Deduplication pass, extracts four shared helpers for four copied patterns across modules, plus two small output fixes

Changes

Refactors

• utils::report_summary replaces the copied
  if dry_run { if verbose { "Would X" } } else { "X" } block in
  mono/config.rs (×2) and mono/watch.rs.
• mono::npm::read_package_json shared reader for
  {repo}/package.json (verbose warnings on unreadable/malformed files), replacing
  duplicated logic in create_mono_repo_package_json and get_watch_command.
• run_timed collapses the six identical
  crate::time! { ctx.runner.run(...) } wrappers across cmake/meson/npm builds.
• config::persist_or_dry_run pins the no mutate/save on dry-run block
  in one place for add_config, remove_config, add_profile, remove_profile.

Fixes

• Watch scripts generate_watch_scripts resolved each lib's watch command twice, reading/parsing every package.json twice and printing every verbose warning twice. Commands are now resolved once.
• Output visibility: per-repo "Cloning {name}" progress now always prints; per-wrap "Generated wrap" messages are now verbose-only in both real and dry-run modes Update failures remain always visible. Updated test_clone_repos_per_repo_lines_always_shown accordingly.

Tests

• Direct unit tests for two new public helpers whose paths existing tests didn't exercise: report_summary (full dry-run + verbose) and read_package_json (missing-file and malformed-JSON branches + verbose).