New brainfs PutRegular (create or replace), CreateRegular (create only), AppendRegular, Remove and RealParent: missing parents created one component at a time through the root, every existing component a real directory, new files created with O_EXCL and confirmed before writing. brain_write, promote/reject (O_EXCL create, source kept on refusal), StampProvenanceFile, BuildWingIndex, RebuildIndex, AppendLog and the tunnel candidate log use them; provenance.ApplyFile removed. Fixes #188. Refs #158. Adversarial review: BLOCKED, BLOCKED, PASS. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Co-authored-by: Mathias <mthbqv@gmail.com>