Mission Run Overview
Mission Run: Cross-OS Primitive Unification
Give Spec Kitty's cross-OS lock, safe-delete, and OS-detection primitives one canonical owner each, so Windows PermissionError regressions like #4703 are prevented by construction instead of patched again.
PR #4709 point-fixed the #4703 Windows P0 (every command died with '[Errno 13] Permission denied' from a self-held mandatory lock), but the landing squad confirmed the underlying primitives are forked with no canonical owner — that fork is why the bug class recurs. This mission consolidates the safe-delete helper family, promotes a single OS-detection kernel seam, unifies the ~12-way lock fork behind one sync+async sidecar primitive that can never expose a held lock for reading, and adds a DIRECTIVE_043-governed gate so raw locking primitives cannot re-fork.