docs: document peer quick links

[roziscoding]

Documents the quick link feature from #85 on the docs site.

New page

website/guide/quick-links.md (Guide -> Operating jack), covering:

• what a quick link carries and the jack-link:v1: shape
• setting up the jack.external profile under Settings -> Quick linking, with the HTTPS tip and a warning against pasting jack.internalUrl into the external URL
• generating a link: the fields, the fresh peer API key minted per link, and the one-time plaintext reveal
• importing: prefilled Add peer form, nothing saved until submit, malformed links rejected outright
• revoking: revoke the key by the name you gave it; removing jack.external only blocks new links
• link format: the decoded payload, no encryption, the decode rules, and a link to the generated POST /quick-links operation page

Cross-links

• guide/peering.md - quick links as the low-friction path to the same peering, and as a source of peer API keys
• guide/management-ui.md - Settings -> Quick linking bullet plus a section on both buttons
• reference/configuration.md - jack.external documented (instanceName, url, headers), quick-reference rows, reserved-header rules, the note that header secrets resolve only at generation time, and the block added to the full example

bun run build passes in website/; all new anchors resolve in the built HTML.

[greptile-apps]

Greptile Summary

The PR documents peer quick links and integrates the new guide into the existing documentation.

• Adds a quick-links guide covering setup, generation, import, revocation, and link format.
• Documents the jack.external configuration fields and secret-resolution lifecycle.
• Adds navigation and cross-links from the management UI and peering guides.

Confidence Score: 5/5

The documentation-only PR appears safe to merge.

The previously reported secret-resolution mismatch has been corrected, and no blocking failure remains.

_{Reviews (2): Last reviewed commit: "chore: clarify secret resolution" | Re-trigger Greptile}