6. Feature: Add Connections page for OPC-UA, MQTT, and BACnet

[smithaldon1]

Parent Epic

#206

Purpose

Add a Workbench page for defining and testing protocol connection profiles.

Acceptance Criteria

• Supports OPC-UA, MQTT, and BACnet profile forms.
• Uses protocol-specific controls without exposing raw secret values.
• Shows enabled/disabled state, last test result, health, and validation errors.
• Calls the connection profile API and read-only test endpoint.
• Clearly separates test connection from ingestion start and from industrial writeback.

Implementation Order

Step 6. Depends on the operator-console shell and connection API.

Test Plan

Frontend tests for form validation/redaction plus Playwright flow for creating a disabled profile and running a fake test.