Add protocol Connections page

[smithaldon1]

Closes #212

Summary

• Add /connections to the operator-console Workbench and promote the sidebar Connections slot from planned to a real route.
• Simplify the loaded Connections page to only show the page title, the + add button, and the connections table.
• Replace the inline profile form with a + button that opens a profile-definition modal.
• Show connections in a table with connection display name, status, protocol, last test result, and a read-only test action.
• Use the connection display name as a link that opens the profile-definition modal with prefilled values.
• Add typed Workbench API client support for listing, creating, updating, and testing connection profiles.
• Keep test connection separate from ingestion start and industrial writeback; no writeback controls are added.

Test Evidence

• npm test - passed, 16 tests.
• npm run lint - passed.
• npm run typecheck - passed.
• npm run build - passed; /connections included as a dynamic route.
• npm run test:e2e - blocked because http://127.0.0.1:8000/health was already used by an existing local API server.
• npx playwright test --config /private/tmp/fip-issue212.playwright.config.js against the existing local API/web servers on ports 8000/3000 - passed, 1 test, including the simplified Connections page, opening the add modal, creating a disabled OPC-UA profile, reopening the modal from the display-name table link with prefilled values, and running the read-only test flow.
• Prior full repo validation on this branch: make docs passed, make lint passed, make typecheck passed, make test passed with 239 tests.
• git diff --check and git diff --cached --check - passed.

Docs Impact

• Updated apps/web/README.md with /connections, connection profile API client coverage, the modal/table interaction, and the no-ingestion/no-writeback boundary.
• Updated docs/LEARNING_LOG.md with the Connections page learning summary.

Follow-up Work

• Implement Protocol Diagnostics page using the same redacted profile and test-result contracts.
• Keep live adapter sessions, ingestion start controls, tag/source browsing, and industrial writeback out of this page until their dedicated issues define and test those boundaries.

[smithaldon1]

Reviewed and approved for merge