[vanedaltro]

Main already contains the pending FileChanged owner replacement fix through #80. This PR now resolves the add/add conflict in its verification note and retains the stronger recorded evidence: the regression failed against unchanged main production code with 257 replacement tasks, and strict OpenSpec validates 114 items.

The resolved tree differs from current main in exactly one Markdown file. The observer implementation, focused workflow and task list are byte-for-byte identical to main. Task 5.2 and the separate native admission/protocol gates remain open.

Verification

• Strict OpenSpec: 114 passed, zero failures.
• Spec lint: zero errors and 25 warnings.
• Diff/whitespace check passes; no runtime or workflow behavior changes.
• Historical implementation checks at a7b7688 passed 58 library tests, 24 HTTP lifecycle tests, all-targets cyber-tools Clippy, the exact missing-fix control and restored regression.
• Current-head documentation CI passes: two checks succeeded and six code checks were intentionally skipped for the Markdown-only diff. The prospective merge tree equals the tested head tree.