feat: Add Infrahub Jinja2 transform for VRF/L3VNI configuration (#21) (#25)
## Summary
Implements Infrahub Jinja2 Transform for VRF/L3VNI configuration, generating structured JSON payloads from Infrahub intent data. Closes #21.
## What's included
- **GraphQL query** (`transforms/queries/vrf_intent.gql`): Queries `InfraVRFDeviceAssignment` by device name, fetching VRF details, L3VNI, route targets, and device-specific route distinguisher
- **Jinja2 transform** (`transforms/templates/vrf_yang.j2`): Renders VRF config payloads with defensive null handling (lessons learned from #20)
- **`.infrahub.yml`** updated with the new query and transform definitions
- **Tests** (`transforms/tests/vrf_yang/`) using correct Infrahub pytest format (`jinja2-transform-smoke` + `jinja2-transform-unit-render`)
## Validation
All transforms render correctly:
| Device | Expected | Result |
|--------|----------|--------|
| `leaf3` | VRF gold, RD `10.0.250.13:1`, L3VNI 100001 | ✅ |
| `leaf7` | VRF gold, RD `10.0.250.17:1`, L3VNI 100001 | ✅ |
| `leaf1` | Empty array (no VRF assignment) | ✅ |
| `spine1` | Empty array (no VRF assignment) | ✅ |
## Usage
```bash
# Local debugging
infrahubctl render vrf_yang_transform device_name=leaf3
# API endpoint
GET /api/transform/jinja2/vrf_yang_transform?device_name=leaf3
```
## Related
- Depends on: #20 (base transforms infrastructure, already merged)
- Reference: Arista EVPN Type-5 / L3VXLAN configuration from lab topology
Damien Arnodo
a105e44bbd