Apache Pig API Rules

# apache-pig — Spectral ruleset (strengthened)
# Plain Spectral. Existing hand-authored rules preserved; measured rules added
# from this provider's own OpenAPI conventions by strengthen_ruleset.py,
# then self-validated against the spec.
#
# Provenance:
#   - servers-https-only: 100% of servers already https (error)
#   - path-params-casing: camel @ 100% (n=3)
#   - operationid-casing: camel @ 100% (n=6)
#   - schema-names-casing: pascal @ 100% (n=7)
#   - schema-properties-casing: snake @ 70% (n=23)
#   - error-schema-defined: ValidationError
#   - pagination params observed: ['limit']
#   - merge: kept 5 existing, added 7 measured, upgraded 0
#   - added: servers-https-only, path-params-casing, operationid-casing, schema-names-casing, schema-properties-casing, error-schema-defined, no-empty-descriptions
extends:
  - spectral:oas
rules:
  info-title-required:
    severity: error
    given: $.info
    then:
      field: title
      function: truthy
  operation-summary-required:
    severity: error
    given: $.paths[*][*]
    then:
      field: summary
      function: truthy
  operation-operationId-required:
    severity: error
    given: $.paths[*][*]
    then:
      field: operationId
      function: truthy
  operation-summary-apache-prefix:
    severity: info
    given: $.paths[*][get,post,put,delete,patch].summary
    then:
      function: pattern
      functionOptions:
        match: ^Apache Pig
  response-success-required:
    severity: error
    given: $.paths[*][get,post,put].responses
    then:
      function: schema
      functionOptions:
        schema:
          anyOf:
          - required:
            - '200'
          - required:
            - '201'
  servers-https-only:
    description: Server URLs must use HTTPS.
    severity: error
    given: $.servers[*].url
    then:
      function: pattern
      functionOptions:
        match: ^https://
  path-params-casing:
    description: Path parameters should be camelCase (the dominant convention in this API).
    severity: warn
    given: $.paths[*].parameters[?(@.in=='path')].name
    then:
      function: casing
      functionOptions:
        type: camel
  operationid-casing:
    description: Operation IDs should be camelCase (the dominant convention in this API).
    severity: warn
    given: $.paths[*][get,post,put,patch,delete].operationId
    then:
      function: casing
      functionOptions:
        type: camel
  schema-names-casing:
    description: Component schema names should be PascalCase (the dominant convention in this API).
    severity: warn
    given: $.components.schemas
    then:
      field: '@key'
      function: casing
      functionOptions:
        type: pascal
  schema-properties-casing:
    description: Schema properties should be snake_case (the dominant convention in this API).
    severity: info
    given: $.components.schemas[*].properties
    then:
      field: '@key'
      function: casing
      functionOptions:
        type: snake
  error-schema-defined:
    description: A shared error schema (ValidationError) should be defined for error payloads.
    severity: warn
    given: $.components.schemas
    then:
      field: ValidationError
      function: truthy
  no-empty-descriptions:
    description: Descriptions must not be empty strings.
    severity: warn
    given: $..description
    then:
      function: truthy