docs: refresh README and make OpenWiki manual

[christopherjnelson]

StoryRail's README described implemented automation and publishing features as future work, and the scheduled OpenWiki workflow created ongoing generated documentation maintenance. This change shortens and updates the overview, adds factual project badges and screenshots of the actual UI with fictional demo data, and removes the OpenWiki GitHub Actions workflow.

OpenWiki remains available for optional manual local refreshes. Agent and contributor guidance now reflect that workflow, current runtime configuration, and the PostgreSQL and browser acceptance suites. Existing generated OpenWiki pages are retained. The Next.js-managed agent guidance generated by the acceptance server is included, as the repository instructions request.

No application behavior, dependencies, or tests were changed. Screenshot capture used the existing React components and styles with in-memory sample clients; it did not access a database or provider service.

Verification was executed with the maintainer's explicit authorization:

• Frozen-lockfile installation, scoped Markdown formatting, repository formatting, and whitespace checks passed.
• Lint passed with 12 existing warnings in unchanged files; typecheck passed.
• Unit suite: 1,811 tests passed; the 250 PostgreSQL tests were skipped in this run and executed separately.
• PostgreSQL integration suite: 250 tests passed against an isolated PostgreSQL 18.4 container.
• Browser acceptance: both tests passed, including the supervised editorial journey through WordPress delivery.
• Production build passed outside the sandbox after the sandboxed run lost TypeScript child-process output.

The disposable database container was removed after verification. No OpenWiki generation was run.