[vanedaltro]

Binary editing needs a durable private draft and a recoverable native save before production mutation routes can be enabled. This increment adds bounded expected-byte splices, undo/redo, original-offset byte reviews, private base storage, journaled same-filesystem exchange, operation receipts and reviewed Restore Last Save.

Save retries reuse the original operation identity. Process-death tests cover preparation, intent, native exchange and acknowledgement; uncertain outcomes retain evidence and never automatically repeat the exchange. Full source content is rechecked at commit, and metadata/ACL preservation is verified before acknowledgement. Scoped restart discovery and explicit discard retain receipts/preimages and isolate manual/model namespaces. Private storage is prepared and hidden before child launch.

Text editors and Git snapshot capture/restore now share workspace mutation coordination. File edit admission preserves Plan, sandbox, ownership and private-path ceilings. Owner permission asks require manual confirmation without Auto-classifier inference.

Validation:

• Core library: 368 tests passed; later binary selection: 51 passed. The ignored crash helper is explicitly executed by its parent tests.
• Production App file routes: 17 passed; additional Auto-mode owner approval regression passed separately with zero provider requests.
• Two workspace ownership tests, three actual text/patch/admission tests and nine real Git snapshot tests passed.
• Clippy for core/server/tools/snapshot/App with warnings denied, formatting/diff whitespace and strict OpenSpec (114 items) passed.
• Dedicated native proof passed on Linux/macOS/Windows at 2f8ae42. Current-head CI and the added explicit Linux distinct-mount refusal proof are pending.

Refs #94. This is a core/admission increment: production CLI/TUI and binary owner routes remain read-only. Mutation routes/SDK, manual editing UX, model operations, snapshot/version retention and acknowledged FileChanged integration remain required before closing the issue. Windows native replacement is not implemented; its viewer remains available. The implementation progress document records evidence and platform limits.