specrail-write-tech-spec

# SpecRail Write Tech Spec Use this skill for the technical half of the `write_spec` route. ## Steps 1. Read the linked issue and `docs/specs/GH<issue-number>/product.md`. 2. Read the relevant tech spec template from `templates/<locale>/tech_spec.md` or `templates/tech_spec.md`. 3. Run the local gate when available: ```sh python3 checks/route_gate.py --repo . --route write_spec --issue <issue-number> --state ready_to_spec --json ``` 4. Explore the codebase first, then write `docs/specs/GH<issue-number>/tech.md`. 5. Ground the plan in codebase context: relevant files, current behavior, and why each area changes or stays unchanged, following the anchor discipline below. 6. Map every product behavior invariant to an implementation area and a verification, following the full-coverage rule below. 7. Describe the proposed design, data flow, touched components, edge cases, migration or compatibility risks, verification plan, and rollback plan. 8. Name deterministic checks that prove the design was implemented. ## Anchor discipline Every file reference in Codebase Context is a claim; verify it before writing it down. - Write `path:line` anchors only after confirming them with Read or grep in the current working tree. Do not guess paths, line numbers, function names, or config keys from memory. - If an anchor cannot be verified, either drop the row or mark it explicitly as "待定位 / to locate" — never leave a plausible-looking guess. - Anchors describe the tr...