fix: technical debts left by the Sites, Authors and SEO slices, plus backend support for the new Sites and Authors pagination

features/authors_backend.qa.md

@@ -102,6 +102,13 @@ Spec: `features/authors_backend.feature`. Go tests only, in `test/` (package `te
 57. Scoped mutation run through `task mutate` only, for example `MUTATE_FILES=<author and article use case files> MUTATE_RUN='TestAuthor' MUTATE_WORKERS=2 task mutate -- <use case package path>`; report LIVED and NOT COVERED mutants; re-check filtered suspects without `MUTATE_RUN`. Also run `task lint:go` and `task fmt`.
 58. Docs, checked by reading the files: docs/api.md documents the five /v1/author routes (GET, POST, POST /me, PATCH, DELETE) with auth and roles, error tokens, the author and article-author shapes, `author_ids`, the `/auth/me` `author` field and `authors_updated`; docs/architecture.md names the author aggregate, repository and use cases.
 
+## M. X-Total-Count (Go, `test/`, `task test`)
+
+59. On the same `mockAuthorRepo` and router as item 4, assert `X-Total-Count` equals the decoded body `total` for: size=5 of 30, `q=mar` with 7 matches, `page=3&size=100` (items empty, total 30), `q=nobody` (0), and for owner, admin, "editor" and API key. Assert the header is absent for `size=30`, `page=0`, `page=abc`, unverified (403) and none (401). The body assertions of item 4 stay unchanged.
+60. On the SQLite contract harness, the author list total (and so the header) follows `q` and does not depend on `page`/`size`; `task test:mysql` and `task test:postgres` run the same case.
+61. CORS preflight from an allowed origin exposes `X-Total-Count`.
+62. Scoped `task mutate` on the author list use case and handler files only. `docs/api.md` author row and `web/src/data/apiCatalogue.ts` (`X-Total-Count` response header on `GET /v1/author/`) with its spec, read by hand. No comment added.
+
 ## Manual
 
 - MySQL and Postgres: run the contract suite with the opt-in env vars against real servers.