Review the following Bill of Materials (BOM) for electrical, mechanical, voltage compatibility, missing power components, missing motor drivers, or pinout conflicts.

Bill of Materials:
{bom_json}

Identify issues such as:
1. Voltage mismatches (e.g. 5V logic connected directly to 12V relays without transistors/optocouplers).
2. Missing power supplies or voltage regulators (e.g. 12V valve present but only 5V supply listed).
3. Duplicate or redundant development boards.
4. Impossible combinations or missing connectors/cables.

Respond ONLY with a JSON object conforming to the CompatibilityReport schema.
