Developer API & AI Agent Tool Manifest

<!-- Standard HVACLogic Calculator Embed Snippet -->
<iframe
  src="https://hvaclogic.org/embed/ductulator"
  width="100%"
  height="720"
  style="border: 1px solid #2e3b52; border-radius: 12px; max-width: 960px; width: 100%;"
  title="Digital Ductulator — HVACLogic"
  loading="lazy"
  allow="clipboard-write">
</iframe>
<p style="font-size: 12px; color: #64748b; margin-top: 6px; font-family: sans-serif;">
  Free HVAC calculations referencing ASHRAE & ACCA standards by 
  <a href="https://hvaclogic.org/calculators/ductulator" target="_blank" rel="noopener" style="color: #00d2ff; text-decoration: underline; font-weight: 600;">
    HVACLogic Engineering Suite
  </a>
</p>

// Example: Custom GPT Action / LangChain Tool Definition
{
  "name": "calculate_ac_tonnage",
  "description": "Calculate required residential AC cooling tonnage and design CFM airflow based on floor area and ASHRAE climatic zone.",
  "parameters": {
    "type": "object",
    "properties": {
      "area": { "type": "number", "description": "Conditioned floor area in square feet" },
      "climateZone": { "type": "string", "enum": ["mild", "moderate", "hot_humid", "desert"] },
      "ceilingHeight": { "type": "number", "description": "Average ceiling height in feet (default 8)" }
    },
    "required": ["area", "climateZone"]
  }
}