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.

Inizia da docs/site/src/data/repo-docs.yaml e verifica la voce archive_remote, quindi esegui i controlli markdownlint e vale del repository sui file README, del contratto dell’operatore, di configurazione e del tutorial Evidence indicati. Esamina la configurazione dello stile per individuare eventuali eccezioni di vale relative a falsi positivi. Il lavoro è completato quando il remote è giustificato o organizzativo, i problemi markdown indicati sono risolti e i controlli hanno esito pulito.

Scritto dal modello di indicizzazione a partire dal testo della issue.