docs hygiene: personal archive remote in repo-docs.yaml, pre-existing markdownlint and vale findings

## Context

Found during the review of PR #851 in docs content and lint that the PR did not touch.

## Gaps

- `docs/site/src/data/repo-docs.yaml` points the manifest `archive_remote` at a personal repository (`github.com/jeremi/registry-manifest`) rather than an organization one.
- Pre-existing markdownlint findings: `crates/registry-mint/README.md` MD040 at two fences, `products/evidence/OPERATOR-CONTRACT.md` MD040 and MD022.
- Pre-existing vale findings: a repetition false positive in `products/evidence/CONFIG.md` and a "just" suggestion in the Evidence tutorial page.

## Acceptance

- The archive remote names the organization repository or the entry records why a personal one is right.
- markdownlint and vale are clean on the listed files, with vale exceptions recorded in the style config rather than the prose where the finding is false.

Start with docs/site/src/data/repo-docs.yaml and verify the archive_remote entry, then run the repository's markdownlint and vale checks against the listed README, operator contract, configuration, and Evidence tutorial files. Review the style configuration for any false-positive vale exception. Done means the remote is justified or organizational, the listed markdown findings are resolved, and the checks are clean.

Written by the indexing model from the issue text.