fix(docs): replace dead gnubok.app domain with app.gnubok.se across public docs (#683)

gnubok.app has no DNS delegation (the .app TLD returns no NS records for
it), so every https://gnubok.app/... link in the public docs was dead —
including the OAuth connector URL a Claude Connectors Directory reviewer
would paste from the new Connect-with-Claude page (#682), and the docs
links in the gnubok-mcp npm README that ships in the tarball.

app.gnubok.se is the live production domain (the MCP endpoint there
correctly answers 401 unauthenticated) and was already the default
GNUBOK_URL in the npm bridge and the branding-service appUrl fallback.

Mechanical swap: 55 occurrences across 11 files, all https:// URL form
(verified no emails or identifiers). Docs content only — no code paths.
Also resolves the greptile domain-mismatch finding on #682.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/docs/content/versioning.ts

@@ -24,7 +24,7 @@ Webhooks are pinned to the API version active at creation time (the \`api_versio
 API requests pin per-request via the \`Gnubok-Version\` request header (planned for v1.x; today every request gets the current version):
 
 \`\`\`bash
-curl https://gnubok.app/api/v1/companies \\
+curl https://app.gnubok.se/api/v1/companies \\
   -H "Authorization: Bearer ..." \\
   -H "Gnubok-Version: ${API_V1_VERSION}"
 \`\`\`
@@ -82,7 +82,7 @@ Other endpoints **support** but don't require it. Sending one is always safe.
 ### Pattern
 
 \`\`\`bash
-curl https://gnubok.app/api/v1/companies/{cid}/invoices \\
+curl https://app.gnubok.se/api/v1/companies/{cid}/invoices \\
   -H "Authorization: Bearer ..." \\
   -H "Idempotency-Key: $(uuidgen)" \\
   -H "Content-Type: application/json" \\
@@ -136,8 +136,8 @@ Every successful write response carries an \`audit\` block in \`meta\`:
     "api_version": "${API_V1_VERSION}",
     "audit": {
       "voucher_number": "A-2026-042",
-      "voucher_url": "https://gnubok.app/bookkeeping/...",
-      "audit_trail_url": "https://gnubok.app/audit/req_...",
+      "voucher_url": "https://app.gnubok.se/bookkeeping/...",
+      "audit_trail_url": "https://app.gnubok.se/audit/req_...",
       "immutable_at": "2026-05-15T12:00:00Z"
     }
   }