CUBELinux-2
35e5183193
Integrates Packages 3-5 over a single shared CubeStore, the literal CUBELinux premise (data addressed by coordinate, not path). Adds the cubesys crate (lib + cube CLI + cube-demo) proving two end-to-end properties: a cubefs path IS a runnable code cell at the same coordinate, and a sealed record reopens and runs on the same store. Two latent cross-crate bugs surfaced and fixed while integrating: - cubecoords: refresh_flags() now preserves out-of-band flag bits (8..=15), so cubecrypt's HEADER_FLAG_ENCRYPTED survives refresh. - cubestore: record codec now serializes raw flag bits (TLV tag 12) so the encrypted bit survives the store round-trip. All gates green (./check, incl. cubefs --features mount).