Add Test Stand

Add a validated stand definition that maps stable logical roles to existing physical device IDs.

Inspect

1. Read AGENTS.md completely and follow its approval and verification rules.
2. Read inventory/stands.yaml and every source in its device_files list.
3. Read the inventory Pydantic models and loader when the requested shape is not already supported.
4. List the requested stand name, description, capabilities, logical roles, and referenced device IDs. Ask only for information that cannot be inferred safely.

Design and review

1. Verify that the stand name is unique unless the user explicitly requests an update.
2. Verify every referenced device ID exists across the combined physical-device inventory.
3. Keep stand entries limited to description, capabilities, and role: device_id mappings.
4. Keep hosts, ports, models, transports, and credential references in device inventory files.
5. Keep secrets in runtime settings; never place usernames or passwords in inventory.
6. Prefer descriptive logical roles that remain stable when physical equipment changes.
7. Show the complete proposed stand YAML and identify every file to change.
8. Request explicit approval before modifying files.

Example:

stands:
  stand-03:
    description: Example validation stand
    capabilities: [smoke, measurement]
    devices:
      dut: dut_03
      analyzer_primary: analyzer_01
      analyzer_secondary: analyzer_02

Implement and verify

1. Modify only the approved stand definitions and any approved documentation.
2. Preserve unrelated inventory entries and formatting.
3. Load inventory/stands.yaml through hardware_test.inventory.load_inventory to validate all sources and references.
4. Add or update tests only after production changes are approved, as required by AGENTS.md.
5. Do not connect to physical equipment or run hardware tests unless explicitly requested.
6. Stage the intended changes and run ./scripts/ci.sh.
7. Report the logical-role mapping and verification results.