cross-harness-continuation

# Cross-Harness Continuation Use this skill when a task continues after another agent, especially when the handoff is Claude -> Codex, Codex -> Claude, or a plugin has already received several partial fixes. ## Operating contract The repository is the source of truth for code. The continuation contract is the source of truth for intent that Git cannot express: `<repo>/.claude/continuity/CONTINUITY.json` The canonical shape is in `references/CONTINUITY.example.json`. It must contain: - `mode`: `continuation` for incremental work, `new` for greenfield work; - `baseline`: branch, commit, and paths that were already dirty at handoff; - `scope.files`: the files explicitly claimed for the current slice; - `preserve`: accepted design decisions and invariants; - `do_not_redo`: approaches already tested or deliberately rejected; - `verification`: commands and evidence status; - `scope.enforce` and `scope.protect_unlisted` when the slice must be strict. ## Required sequence 1. Read `CONTINUITY.json`, the newest handoff, `AGENTS.md`/`CLAUDE.md`, and the current Git status. Treat the live checkout as authoritative over stale prose. 2. Verify the baseline commit, branch, dirty paths, and the claimed files. Preserve existing changes unless a test or the contract proves they are wrong. 3. Make one focused continuation change. Use `Edit` for existing files. Do not replace a whole file merely because another implementation is easier to write. 4. Run the smallest rele...