- Add displayName field to AuthTokenResponse so the UI shows human-readable
names instead of internal JWT subjects (e.g. user:oidc:<hash>)
- Add displayNameClaim to OIDC config (default: "name") allowing admins to
configure which ID token claim contains the user's display name
- Support dot-separated claim paths (e.g. profile.display_name) like rolesClaim
- Add admin UI field for Display Name Claim on the OIDC config page
- ClickHouse migration: ALTER TABLE adds display_name_claim column
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
