control-center: remove dead cc-ui (React frontend) code

[man4ish]

Surfaced while investigating #6 (control-center bare-route drift). Not
blocking anything — filed for tracking, per the "flag it rather than leave
it as unexplained drift" standard used elsewhere in this thread.

What's dead

omnibioai-control-center/frontend/cc-ui — a full React/TypeScript SPA
(multiple pages: EcosystemPage.tsx, CloudPage.tsx, LlmPage.tsx, its
own api.ts client, etc.) — is not served anywhere in the current
deployment:

• docker-compose.yml's control-center service builds the Dockerfile's
  target: backend stage only. The Dockerfile has a separate frontend
  stage (nginx on port 5174, serving cc-ui's build + proxying a handful
  of API paths) that is never built or run.
• cc-ui/dist is bind-mounted into the backend container at /app/dist
  (docker-compose.yml), but nothing serves it — zero
  StaticFiles/.mount() calls anywhere in the backend source.
• The page actually served at /_svc/control/ is a completely different,
  self-contained "OmniBioAI Ecosystem" report — generated entirely by
  main.py's root() as one big Python f-string with inline <script>
  tags (confirmed live: <title>OmniBioAI Ecosystem, not cc-ui's
  Vite-built title).

Evidence this is an abandoned pivot, not planned work

• cc-ui's most recent commit (5a4532a, 2026-07-25) is a cosmetic,
  cross-repo domain-rename sweep (app.omnibioai.org →
  webstudio.omnibioai.org in a display string) — not feature work.
• Meanwhile the self-contained root() page has substantial active
  recent development: 803d18b ("Remove header Regenerate/Dashboard
  buttons, gate landing page, retire /dashboard") explicitly deleted a
  ~600-line duplicate dashboard page and consolidated everything into the
  single-page report; a43202d fixed a path-prefix bug in that same
  page's "Docker Images" tab; several other recent commits added an Admin
  tab, cron job management, known-issues CRUD — all directly in
  main.py/scripts/sections/*.py, none in cc-ui.
• Zero mentions of cc-ui anywhere in README.md, and no
  TODO/FIXME/deprecated markers in its own source acknowledging its status
  either way.

Reading: cc-ui was the first-generation Control Center frontend; the
project pivoted to a simpler, self-contained server-rendered page at some
point before 2026-07-26 and never went back to clean up the old SPA or its
now-vestigial dist bind mount.

Suggested fix (low priority, not urgent)

• Remove frontend/cc-ui/ from omnibioai-control-center.
• Remove the Dockerfile's unused frontend stage (port 5174, nginx +
  cc-ui + proxy) — dead code, never built.
• Remove the cc-ui/dist bind mount from omnibioai-studio's
  docker-compose.yml (control-center service).
• Once removed, npm run check-routes should stop reporting cc-ui's
  /config, /report, /services entries as drift (currently documented
  as intentional/expected in docker/nginx-router.conf's KNOWN DRIFT
  comment — that note can come out too once this is done).

Not doing this now — flagging per instruction, not fixing without asking.