add Grok, App Builder (subdomain + apex)

[shamwow]

Description

Two Domain Connect templates for Grok — App Builder (grok.com), pointing a
customer's custom domain at an app deployed with Grok App Builder (Vercel-backed):

• grok.com.app-builder.json — subdomain (e.g. app.example.com): CNAME → %vercelcname%, hostRequired.
• grok.com.app-builder-apex.json — apex (e.g. example.com): A → %vercelapex%.

Routing targets are Vercel's per-project values (CNAME target / apex IP), which vary per
app — so they're template variables supplied at apply time and protected by a signed
synchronous request (syncPubKeyDomain = domainconnect.grok.com, key = _dck1, RS256).

Type of change

• New template

How Has This Been Tested?

• Template functionality checked using Online Editor — subdomain verified; links being added below
• Template file names follow <providerId>.<serviceId>.json
• resource URL provided with logoUrl is actually served (https://grok.com/images/favicon.svg, image/svg+xml)

Both templates pass dc-template-linter -loglevel error -tolerate info -logos (exit 0).

Checklist of common problems (applies to both templates)

• syncPubKeyDomain is set — domainconnect.grok.com
• warnPhishing is not set alongside syncPubKeyDomain
• syncRedirectDomain is set (grok.com) — sync flow uses redirect_uri
• no TXT record contains SPF content — (no TXT records)
• txtConflictMatchingMode — n/a (no TXT records)
• no variable used as a bare full record value — per spec the pointsTo variable MUST be the only content (prefixes/suffixes forbidden), so the CNAME/A targets are bare variables by design; integrity is protected by the request signature
• no bare variable used as the full host label — host is @
• no variable used in the host field to create a subdomain — subdomain template uses the host param + hostRequired
• %host% does not appear explicitly in any host attribute
• essential — n/a

Notes:

• Vercel's ownership-verification TXT (_vercel, vc-domain-verify=<domain>,<token>) is intentionally not templated: it's conditional (only when the domain is already claimed on Vercel), zone-scoped, and dynamic — handled out-of-band.

Online Editor test results

Editor test link(s):

• subdomain (host set) — pending paste
• apex (host empty) — pending paste

[github-actions]

✅ JSON Filename Check Passed

[github-actions]

✅ JSON Schema Validation Passed

[github-actions]

Linter OK

grok.com.app-builder-apex.json

Level	Code	Note

grok.com.app-builder.json

Level	Code	Note

[github-actions]

PR Description Check Failed

The PR description is missing required elements. Please update it according to the PR template.

Details

  OK  Type of change: 1/1 checkboxes ticked

Labels to add: Checklist of common problems not complete, PR description incomplete, Test links missing
Labels to remove: Forged editor links

PR description check FAILED:
  FAIL  'How Has This Been Tested?': 1/3 checkboxes are not ticked
  FAIL  'Checklist of common problems' section not found
  FAIL  'Online Editor test results': no valid editor test link found
  FAIL  Template coverage: grok.com.app-builder-apex.json: no editor test link found (expected template id 'grok.com.app-builder-apex')
  FAIL  Template coverage: grok.com.app-builder.json: no editor test link found (expected template id 'grok.com.app-builder')