AI skill: SKILL.md, AI contract, scrubbed references, eval fixture (d)

- rpa-dashboard-ai/SKILL.md: trigger description and the shared question flow;
  points at the no-AI frontend.md, themes and palette instead of copying them.
- templates/contract.md: runs, review rows, endpoints and the server approve gate.
- Superbill extracts: patient names and the client name removed, every file
  carries an EXAMPLE ONLY banner. tests/test_reference_scan.py checks both skills
  for patient data, internal IPs, credentials and keys.
- tests/fixtures/d-ai-extraction and its eval entry, which runs page_check_ai
  on the built folder.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/fixtures/d-ai-extraction/README.md

@@ -0,0 +1,8 @@
+# Invoice extraction service
+
+A small web service. It sends a scanned invoice to an LLM and gets back the
+invoice fields, each with a confidence score per word. There is no UI yet.
+
+```
+uvicorn app:app --port 8000
+```