Add resource path segment classifier and validation rules

[mo-alras]

Summary

• Introduces ResourceClassifier that classifies RAML resource path segments into 8 categories (COLLECTION, IDENTIFIED_OBJECT, SCOPING_PREFIX, ACTION_ENDPOINT, MATCHING_ENDPOINT, IDENTIFIER_LOOKUP, SINGLETON, UNKNOWN) using structural signals from the RAML model (resource type annotations, URI patterns, HTTP methods, child resources).
• Enhances ResourcePluralRule with classifier guard so it only checks COLLECTION resources, eliminating the need for most manual exclusions in ruleset.xml (the HTTP API currently has 29 exclusions, History API has 21).
• Adds ResourceSingularRule to validate that singleton resources use singular names.
• Adds ScopingOrderRule to validate that scoping prefixes (as-* → in-* → me) appear in the correct composition order.
• Adds ResourceAllowedCharactersRule to validate path segments only contain lowercase letters, digits, and hyphens.
• Adds ResourceNoFileExtensionRule to validate path segments do not contain file extensions.
• Externalizes the action verb whitelist to default-action-verbs.txt (13 verbs), extensible per-API via <option type="action-verb"> in ruleset.xml.
• Adds ACTION_VERB to RuleOptionType enum.
• Reduces ResourcePluralRule.defaultExcludes from 6 entries to 2 ("", "inventory") — the classifier now auto-handles login, me, import, in-store.

Classification logic (first match wins)

1. URI literal contains = → IDENTIFIER_LOOKUP
2. URI is /{variable} → IDENTIFIED_OBJECT
3. Path starts with as-/in- or equals me → SCOPING_PREFIX
4. Path starts with matching- → MATCHING_ENDPOINT
5. Resource type is baseDomain → COLLECTION
6. Resource type is baseResource → IDENTIFIED_OBJECT
7. Has child with /{var} or /key={key} → COLLECTION
8. Path matches action verb whitelist or POST-only leaf → ACTION_ENDPOINT
9. Has GET, no ID children → SINGLETON
10. Has non-trivial children → COLLECTION
11. Otherwise → UNKNOWN

Follow-up: commercetools-docs cleanup

After this PR is merged and released, a follow-up PR in commercetools/commercetools-docs should:

1. Bump rmf-codegen version in api-specs/*/package.json
2. Clean up ruleset.xml exclusion lists — most ResourcePluralRule exclusions become unnecessary:
   • api-specs/api: 29 → ~1-2 (keep inventory, verify password)
   • api-specs/history: 21 → ~1
   • api-specs/connect: 1 → 0
   • api-specs/checkout: 2 → 0-1
   • api-specs/insights: 1 → 0
3. Add new rules to each ruleset.xml:

   <rule><name>com.commercetools.rmf.validators.ResourceSingularRule</name></rule>
   <rule><name>com.commercetools.rmf.validators.ScopingOrderRule</name></rule>
   <rule><name>com.commercetools.rmf.validators.ResourceAllowedCharactersRule</name></rule>
   <rule><name>com.commercetools.rmf.validators.ResourceNoFileExtensionRule</name></rule>

Test plan

• All 91 existing + new tests pass (./gradlew :ctp-validators:test)
• Verify against commercetools HTTP API spec after release
• Verify against History, Connect, Checkout, Insights, Import API specs

🤖 Generated with Claude Code

[jenschude]

This prompt should be re-run as it deleted older test cases