Feature: split overview and add context questions

[smithaldon1]

Summary

• Closes Feature: Split overview dashboard from Process Sentinel workflows and add context Q&A #243.
• Adds POST /context/questions with deterministic, read-only intent matching over existing browser-safe API data.
• Adds the overview context question form directly under the dashboard title with supported, partial, unsupported states and source links.
• Moves Process Sentinel into a dedicated /process-sentinel workflow entry route and keeps Overview outside the Sentinel workflows nav group.
• Updates Workbench/API docs and the learning log for the new endpoint and IA boundary.

Test Evidence

• PASS: .venv/bin/python -m pytest services/api/tests/test_api.py
  • 24 passed
• PASS: npm test
  • 20 passed
• PASS: make lint
  • All checks passed
• PASS: make typecheck
  • compileall completed
• PASS: make test
  • 298 passed, 4 skipped
• PASS: cd apps/web && npm run lint
  • eslint completed with zero warnings
• PASS: cd apps/web && npm run typecheck
  • tsc --noEmit completed
• PASS: make test-e2e
  • 1 passed

Docs Impact

• Updated apps/web/README.md with the overview context question endpoint and /process-sentinel route.
• Updated services/api/README.md with POST /context/questions behavior and safety limits.
• Updated docs/demo/OPERATIONS_WORKBENCH_INFORMATION_ARCHITECTURE.md with the global overview and Process Sentinel route boundary.
• Added a docs/LEARNING_LOG.md entry.

Follow-Up Work

• Plan any AI-backed context assistant separately around the documented local model gateway and Factory Memory direction.
• Keep future answers constrained to browser-safe data unless a reviewed API contract expands the source set.