Adds GET /api/v1/demo/manifest as a single source of truth for the demo's
fictional org identity (Northstar Mobility -- surfacing the project's
already-locked tenant name), synthetic-data/reset state, and live scenario
readiness. Rewrites the login screen in Dutch with an honest, no-password
demo entry and a guided-demo entry point, replaces the loud full-width
demo banner with a subtle badge + popover, and adds a compact About page
explaining what's real vs. synthetic vs. not yet connected.
Add the new endpoints to contracts/openapi.yaml and docs/05-api-contract.md
(return-preview, the four rule-specific data-quality resolution endpoints,
search, integration status, scheduled-scan), document the role matrix and
the audit before/after exposure in docs/12-security-and-audit.md, document
each rule type's actual resolution flow in docs/07-data-quality.md
(including the deliberate evidence-fingerprint simplification and the
reopened_from/previous_decision recurrence link), document the preview/
commit relationship in docs/08-return-workflow.md, and update README.md's
scope/integration-status/quality-gate sections to match what's actually
implemented and verified now. Also drops docs/05-api-contract.md's mention
of GET /api/v1/system/status, which was never implemented.