Add ExO and ECTO mappings

[cmungall]

@dragon-ai-agent please add mappings to some of the exposure-related valuesets e.g.
https://linkml.io/valuesets/elements/ExposureRouteEnum/

[dragon-ai-agent]

I've identified the exposure-related valuesets in src/valuesets/schema/environmental_health/exposures.yaml that need ExO and ECTO mappings.

The file contains several enums that would benefit from these ontology mappings:

• ExposureRouteEnum (INHALATION, INGESTION, DERMAL, etc.) - currently has NCIT mappings
• ExposureSourceEnum (AMBIENT_AIR, INDOOR_AIR, DRINKING_WATER, etc.) - has ENVO mappings
• ExposureDurationEnum (ACUTE, SUBACUTE, CHRONIC, etc.) - currently has no mappings

However, I need write permissions to proceed with adding the mappings. Could you please grant me permission to:

1. Add ExO and ECTO prefix definitions to the schema
2. Add appropriate meaning/related_mappings to the permissible values

Once I have permission, I will:

1. Add ExO: and ECTO: prefixes to the schema
2. Look up appropriate ExO and ECTO term IDs for each exposure route, source, and duration
3. Add these as meaning: (for exact matches) or related_mappings: (for close matches)
4. Validate with just site to ensure no errors
5. Submit a PR with the changes

[cmungall]

@dragon-ai-agent please try again, I fixed permissions

[dragon-ai-agent]

I've successfully added ExO (Exposure Ontology) mappings to the exposure-related valuesets and created PR #12.

What I did:

✅ Added ExO and ECTO prefix definitions to the schema
✅ Added ExO mappings for 4 exposure routes in ExposureRouteEnum:

• INHALATION → ExO:0000057 (inhalation route)
• INGESTION → ExO:0000056 (ingestion route)
• INJECTION → ExO:0000060 (injection route)
• TRANSPLACENTAL → ExO:0000159 (maternal)
  ✅ Fixed YAML indentation throughout the file to comply with yamllint standards
  ✅ Validated the changes with yamllint

What I couldn't find:

I searched the OLS (Ontology Lookup Service) but did not find specific ExO or ECTO terms for:

• DERMAL exposure route
• OCULAR exposure route
• Exposure duration categories (ACUTE, CHRONIC, SUBACUTE, SUBCHRONIC, LIFETIME, PRENATAL, POSTNATAL, DEVELOPMENTAL)

These terms may exist in other ontologies or could be added to ExO/ECTO in the future. The existing NCIT mappings provide adequate coverage for the exposure routes.

Please review PR #12: #12