feat: Add LLM prompt for API endpoint consistency (#949)

* Add LLM prompt for API endpoint consistency (fixes #944)

- Add .cursor/rules/api-endpoint-consistency.mdc: checklist that applies
  when editing app/controllers/api/v1, spec/requests/api/v1, or
  test/controllers/api/v1. Enforces (1) Minitest-only behavioral coverage
  for new endpoints, (2) rswag docs-only (no expect/assert), (3) same
  API key auth pattern in all rswag specs.
- Reference the rule in AGENTS.md under API Development Guidelines.

* Add tests for API endpoint consistency implementation

- Minitest: test/api_endpoint_consistency_rule_test.rb checks rule file
  exists, globs, and all three sections (Minitest, rswag docs-only,
  API key auth) plus AGENTS.md reference.
- Standalone: test/support/verify_api_endpoint_consistency.rb runs
  same checks without loading Rails (use when app fails to boot).
- Rule: add mdc: links for Cursor, note valuations_spec OAuth outlier.

* Address review: add --compliance check, CLAUDE.md section

- Verification script: --compliance scans current APIs and reports
  rswag OAuth vs API key, missing Minitest for controllers, expect/assert.
- CLAUDE.md: add Post-commit API consistency subsection under
  API Development Guidelines (links to rule, documents script + --compliance).

---------

Co-authored-by: mkdev11 <jaysmth689+github@users.noreply.github.com>

test/api_endpoint_consistency_rule_test.rb

@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+# Verifies the API endpoint consistency implementation (issue #944): rule file and AGENTS.md.
+# If Rails fails to load (e.g. Sidekiq::Throttled), run the standalone script instead:
+#   ruby test/support/verify_api_endpoint_consistency.rb
+
+require "test_helper"
+
+class ApiEndpointConsistencyRuleTest < ActiveSupport::TestCase
+  RULE_PATH = ".cursor/rules/api-endpoint-consistency.mdc"
+  AGENTS_PATH = "AGENTS.md"
+
+  def root
+    @root ||= Rails.root
+  end
+
+  test "rule file exists" do
+    assert File.exist?(root.join(RULE_PATH)), "Expected #{RULE_PATH} to exist"
+  end
+
+  test "rule has globs for API v1 paths" do
+    content = File.read(root.join(RULE_PATH))
+    assert_includes content, "app/controllers/api/v1"
+    assert_includes content, "spec/requests/api/v1"
+    assert_includes content, "test/controllers/api/v1"
+  end
+
+  test "rule includes Minitest behavioral coverage section" do
+    content = File.read(root.join(RULE_PATH))
+    assert_includes content, "Minitest behavioral coverage"
+    assert_includes content, "test/controllers/api/v1/{resource}_controller_test.rb"
+    assert_includes content, "api_headers"
+    assert_includes content, "X-Api-Key"
+  end
+
+  test "rule includes rswag docs-only section" do
+    content = File.read(root.join(RULE_PATH))
+    assert_includes content, "rswag is docs-only"
+    assert_includes content, "expect"
+    assert_includes content, "assert_"
+    assert_includes content, "run_test!"
+    assert_includes content, "rswag:specs:swaggerize"
+  end
+
+  test "rule includes same API key auth section" do
+    content = File.read(root.join(RULE_PATH))
+    assert_includes content, "Same API key auth"
+    assert_includes content, "ApiKey.generate_secure_key"
+    assert_includes content, "plain_key"
+    assert_includes content, "Doorkeeper"
+  end
+
+  test "AGENTS.md references post-commit API consistency" do
+    assert File.exist?(root.join(AGENTS_PATH)), "Expected #{AGENTS_PATH} to exist"
+    content = File.read(root.join(AGENTS_PATH))
+    assert_includes content, "Post-commit API consistency"
+    assert_includes content, "api-endpoint-consistency.mdc"
+    assert_includes content, "Minitest"
+    assert_includes content, "rswag"
+    assert_includes content, "X-Api-Key"
+  end
+end