Redesign Workbench shell as operator console

[smithaldon1]

Closes #214

Summary

• Redesign the Workbench shell around a persistent operator-console sidebar.
• Align the shell color scheme with Demo Factory: pale steel workspace, dark industrial navigation, teal operational accents, amber warning states, and red danger states.
• Remove the horizontal top bar; keep demo mode, API target, read-only diagnostics, and disabled writeback status inside the persistent sidebar.
• Preserve existing Sentinel routes for Overview, Detections, Recommendations, and RCA/CAPA Draft.
• Add planned navigation slots for Connections, Protocol Diagnostics, and Tag/Source Browser without implementing those pages or any production writeback controls.
• Preserve simulator-backed demo safety language in the shared shell.

Test Evidence

• npm test - passed, 15 tests.
• npm run lint - passed.
• npm run typecheck - passed.
• npm run build - passed.
• npm run test:e2e - blocked by existing service on http://127.0.0.1:8000/health; Playwright reported the configured web server URL is already used.
• Earlier alternate-port e2e check on this PR branch: npx playwright test --config /private/tmp/fip-issue214.playwright.config.js against ports 8001/3001 - passed, 1 test.
• Earlier rendered QA on this PR branch: page title Operations Workbench, sidebar/status strip detected, no console warnings/errors, screenshots saved under /private/tmp/fip-214-*.png.
• make docs - passed placeholder docs target.
• make lint - passed.
• make typecheck - passed.
• make test - passed, 239 tests.
• git diff --check and git diff --cached --check - passed.

Docs Impact

• Updated apps/web/README.md with operator-console shell notes, Demo Factory-style palette notes, embedded sidebar status strip, and planned protocol slots.
• Updated docs/LEARNING_LOG.md.

Follow-up Work

• Implement 6. Feature: Add Connections page for OPC-UA, MQTT, and BACnet #212 next: Connections page.
• Keep live protocol diagnostics, tag/source browsing, and production writeback controls out of this shell PR.

[smithaldon1]

Reviewed and approved for merge