Document evidence-based OpenCode compatibility

test/readme_contract_test.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class ReadmeContractTest < Minitest::Test
+  README = File.read(File.expand_path("../README.md", __dir__))
+
+  def test_server_compatibility_points_to_exact_certification_evidence
+    assert_includes README, "https://github.com/ajaynomics/opencode-compat"
+    assert_includes README, "manifests/image-matrix.json"
+    assert_includes README, "manifests/runtime-tuples.json"
+    refute_match(/OpenCode server\s*(?:>=|≥)\s*\d/, README)
+  end
+
+  def test_release_guidance_does_not_claim_trusted_publishing_is_configured
+    assert_includes README, "not configured as of `0.0.1.alpha7`"
+    assert_includes README, "does not currently guarantee publication"
+  end
+end