[linkdata]

Closes #147. Closes #351. Part of #106.

Summary

• Add GitHub OAuth2 profile sign-in and GitLab OIDC sign-in through jawsauth. Account linking requires proof of both provider identities and preserves one identity per provider.
• Serve user routes on the existing linkdata/webserv listener. Render login, account, and browser error pages through JaWS, including admin browser failures.
• Keep OAuth users separate from local password administrators. Bound guest session admission and serialize durable link writes with logout, auth expiry, and session rotation.
• Document provider setup, privacy, and limits.

Dependency

Pins merged jawsauth PR #21 at commit 1748e00.

Verification

• GOWORK=off go test -race -count=1 ./...
• GOWORK=off go vet ./...
• Focused OAuth link, logout, and rotation race tests passed against merged jawsauth.
• git diff --check
• Upstream jawsauth CI, Keycloak OIDC, and GitLab OAuth2 profile sign-in and linking passed.

The opt-in live collaboration test was not run.