Moves three project-level handlers (--copy-project,
--zone-summary, --bench-bake-project) out of main.cpp into a
new cli_project_actions.{hpp,cpp} module. None of these fit
the more-specific modules: copy-project does recursive
project-tree duplication, zone-summary collapses validate +
content rollup into one CI-friendly command, bench-bake-project
times per-zone WHM/WOT load to track perf regressions.
main.cpp shrinks by 243 lines (1,187 to 944). Both --json
output modes preserved for CI pipelines.
