feat(cli): add open-reuse validate and register portfolio integrations

Implement Integration Definition validator CLI with schema and index checks,
pytest suite, and CI workflow. Register open-cmis-tck and issue-core-gitea in
the integration index.

Closes OPEN-WP-0003 and OPEN-WP-0004.

tests/test_validate.py

@@ -0,0 +1,120 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from open_reuse.registry import PACKAGE_ROOT, resolve_repo_root
+from open_reuse.validate import run_validate, validate_definition
+from open_reuse.registry import load_schema
+
+FIXTURES = Path(__file__).parent / "fixtures"
+REPO_ROOT = resolve_repo_root()
+SCHEMA = load_schema(REPO_ROOT)
+MARKITECT_QUARKDOWN = Path("/home/worsch/markitect-quarkdown/integration/quarkdown.integration.yaml")
+
+
+def test_valid_fixture_passes_schema() -> None:
+    errors, warnings = validate_definition(FIXTURES / "valid.integration.yaml", SCHEMA)
+    assert errors == []
+    assert warnings == []
+
+
+def test_invalid_fixture_fails_schema() -> None:
+    errors, warnings = validate_definition(FIXTURES / "invalid.integration.yaml", SCHEMA)
+    assert errors
+    assert any("schema error" in item for item in errors)
+
+
+@pytest.mark.skipif(not MARKITECT_QUARKDOWN.is_file(), reason="markitect-quarkdown not present")
+def test_markitect_quarkdown_reference_passes_schema() -> None:
+    errors, warnings = validate_definition(MARKITECT_QUARKDOWN, SCHEMA)
+    assert errors == []
+
+
+def test_validate_command_success_on_fixture() -> None:
+    code = run_validate(
+        root=REPO_ROOT,
+        targets=[FIXTURES / "valid.integration.yaml"],
+        repos_base=None,
+        fail_on_warnings=False,
+        check_index=False,
+        indexed_only=False,
+    )
+    assert code == 0
+
+
+def test_validate_command_fails_on_invalid_fixture() -> None:
+    code = run_validate(
+        root=REPO_ROOT,
+        targets=[FIXTURES / "invalid.integration.yaml"],
+        repos_base=None,
+        fail_on_warnings=False,
+        check_index=False,
+        indexed_only=False,
+    )
+    assert code == 1
+
+
+def test_index_requires_fields() -> None:
+    code = run_validate(
+        root=REPO_ROOT,
+        targets=[],
+        repos_base=None,
+        fail_on_warnings=False,
+        check_index=True,
+        indexed_only=True,
+    )
+    assert code == 0
+
+
+@pytest.mark.skipif(not MARKITECT_QUARKDOWN.is_file(), reason="markitect-quarkdown not present")
+def test_index_consistency_with_repos_base() -> None:
+    code = run_validate(
+        root=REPO_ROOT,
+        targets=[],
+        repos_base=Path("/home/worsch"),
+        fail_on_warnings=False,
+        check_index=True,
+        indexed_only=True,
+    )
+    assert code == 0
+
+
+def test_active_without_maintainers_warns_with_fail_on_warnings() -> None:
+    active_fixture = FIXTURES / "active-missing-maintainers.integration.yaml"
+    active_fixture.write_text(
+        """
+schema_version: open-reuse.integration.v0.1
+id: active-missing-maintainers
+name: Active Missing Maintainers
+status: active
+owner: open-reuse
+upstream:
+  name: Example Upstream
+reuse:
+  primary_reuse_mode: adapter
+boundary:
+  type: adapter
+  local_adapter: fixture.adapter.Adapter
+validation:
+  harness: python3 -m pytest
+maintenance:
+  escalation_conditions:
+    - validation failure
+""".strip()
+        + "\n",
+        encoding="utf-8",
+    )
+    try:
+        code = run_validate(
+            root=REPO_ROOT,
+            targets=[active_fixture],
+            repos_base=None,
+            fail_on_warnings=True,
+            check_index=False,
+            indexed_only=False,
+        )
+        assert code == 1
+    finally:
+        active_fixture.unlink(missing_ok=True)