docs: add Okta OIDC SSO integration guide

[saif-at-scalekit]

Context

Okta OIDC is fully supported by Scalekit but there is no integration guide for it. Only the SAML guide (okta-saml.mdx) exists. A customer (Hiver, issue #508) explicitly requested this as their highest priority.

What's needed

Create src/content/docs/guides/integrations/sso-integrations/okta-oidc.mdx modelled on microsoft-entraid-oidc.mdx, covering:

1. Get the redirect URI from the SSO Configuration Portal
2. Create an OIDC app integration in Okta (OIDC → Web Application)
3. Configure the redirect URI
4. Get the Client ID and Client Secret
5. Get the Issuer URL (https://{okta-domain}/oauth2/default)
6. Configure API permissions / scopes (openid, profile, email)
7. Assign users and groups
8. Configure the SSO portal with credentials
9. Test the connection
10. Enable the connection

Also update src/components/templates/_sso-integrations.mdx to add the Okta OIDC card alongside the existing Okta SAML card.

References

• Pylon issue fix: resolve OOM (exit code 137) during Netlify builds #508
• Existing template: microsoft-entraid-oidc.mdx
• Draft file already written at src/content/docs/guides/integrations/sso-integrations/okta-oidc.mdx (stashed locally)

[saif-at-scalekit]

Closing — already exists at .