Add Claude rules for testing and pointers to AGENTS.md

.claude/rules

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+../dev/rules

dev/rules/python-testing-integration.md

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+---
+paths:
+  - "tests/integration/**/*.py"
+---
+
+# Integration test rules
+
+Integration tests run against a real Infrahub instance via testcontainers. Use them for anything that depends on Infrahub's actual behaviour: node creation, branch operations, schema loading, queries. Do not use `httpx_mock` in integration tests.
+
+## Test class structure
+
+Inherit from `TestInfrahubDockerClient` and mix in a schema class when your tests require a custom schema. Use class-scoped fixtures for dataset setup so Infrahub is only populated once per test class:
+
+```python
+class TestInfrahubNode(TestInfrahubDockerClient, SchemaAnimal):
+    @pytest.fixture(scope="class")
+    async def base_dataset(
+        self,
+        client: InfrahubClient,
+        load_schema: None,
+    ) -> None:
+        await client.branch.create(branch_name="branch01")
+
+    async def test_query_branches(self, client: InfrahubClient, base_dataset: None) -> None:
+        branches = await client.branch.all()
+        assert "main" in branches
+```
+
+## Client fixture
+
+The `client` fixture provides an authenticated `InfrahubClient` connected to the testcontainer instance. Do not construct a client manually in integration tests.
+
+## Cleanup
+
+Clean up any nodes, branches, or schema changes created during a test class. Use class-scoped fixtures with `yield` to ensure teardown runs even on failure:
+
+```python
+@pytest.fixture(scope="class")
+async def created_branch(self, client: InfrahubClient) -> AsyncGenerator[str, None]:
+    await client.branch.create(branch_name="test-branch")
+    yield "test-branch"
+    await client.branch.delete(branch_name="test-branch")
+```

dev/rules/python-testing-unit.md

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+---
+paths:
+  - "tests/unit/**/*.py"
+---
+
+# Unit test rules
+
+Unit tests cover pure logic, data transformations, schema parsing, and error handling. Use `httpx_mock` to simulate HTTP responses at the transport boundary. Do not substitute a mocked unit test for behaviour that depends on Infrahub's actual server responses — write an integration test for that.
+
+## HTTP mocking with `httpx_mock`
+
+Add the module-level marker when any fixture or test in the file reuses mocked responses:
+
+```python
+pytestmark = pytest.mark.httpx_mock(can_send_already_matched_responses=True)
+```
+
+Use `is_reusable=True` on fixtures that serve multiple tests:
+
+```python
+@pytest.fixture
+async def mock_branch_list(httpx_mock: HTTPXMock) -> HTTPXMock:
+    httpx_mock.add_response(
+        method="POST",
+        json={"data": {"Branch": [...]}},
+        match_headers={"X-Infrahub-Tracker": "query-branch-all"},
+        is_reusable=True,
+    )
+    return httpx_mock
+```
+
+## Testing both async and sync clients
+
+Use the `BothClients` fixture from `tests/unit/sdk/conftest.py` when behaviour must be verified for both client variants. Parametrize over `["standard", "sync"]`:
+
+```python
+@pytest.mark.parametrize("client_type", ["standard", "sync"])
+async def test_branch_list(clients: BothClients, client_type: str, mock_branch_list: HTTPXMock) -> None:
+    if client_type == "standard":
+        branches = await clients.standard.branch.all()
+    else:
+        branches = clients.sync.branch.all()
+    assert list(branches.keys()) == ["main", "branch01"]
+```
+
+Assert the actual expected value. Assertions like `assert result is not None` or `assert result` do not verify behaviour — they only confirm something was returned.
+
+## Test file layout
+
+Mirror the source structure:
+
+```text
+infrahub_sdk/client.py           → tests/unit/sdk/test_client.py
+infrahub_sdk/ctl/commands/get.py → tests/unit/ctl/test_get.py
+```
+
+## No external dependencies
+
+Unit tests must not connect to external services, local file access is fine. If a test requires a running Infrahub instance, it belongs in `tests/integration/`.

dev/rules/python-testing.md

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+---
+paths:
+  - "tests/**/*.py"
+---
+
+# Python testing rules
+
+## No `unittest.mock`
+
+Do not use `unittest.mock`, `MagicMock`, or `patch`. The only sanctioned mocking tools are:
+
+- `httpx_mock` (pytest-httpx) — for intercepting HTTP calls at the transport layer
+- `monkeypatch` — for patching stdlib functions (for example: `ssl.create_default_context`)
+
+## Async tests
+
+`asyncio_mode = "auto"` is configured globally. Do not add `@pytest.mark.asyncio`. Do not add loop scope markers manually — this is handled in `conftest.py`.
+
+```python
+# Correct
+async def test_client_fetches_branch(httpx_mock: HTTPXMock) -> None:
+    ...
+
+# Wrong — decorator not needed
+@pytest.mark.asyncio
+async def test_client_fetches_branch(httpx_mock: HTTPXMock) -> None:
+    ...
+```
+
+## Parametrized tests
+
+Use a dataclass with `name` as the first field and pass it as the `id` in `pytest.param`. Always use keyword arguments when constructing cases:
+
+```python
+@dataclass
+class BranchCase:
+    name: str
+    branch_name: str
+    expected_conflict: bool
+
+BRANCH_CASES = [
+    BranchCase(name="no-conflict", branch_name="feature-x", expected_conflict=False),
+    BranchCase(name="conflict", branch_name="main", expected_conflict=True),
+]
+
+@pytest.mark.parametrize("case", [pytest.param(tc, id=tc.name) for tc in BRANCH_CASES])
+async def test_branch_conflict(case: BranchCase) -> None:
+    ...
+```
+
+## Exception assertions
+
+Always pass `match=` to `pytest.raises()`:
+
+```python
+with pytest.raises(NodeNotFoundError, match="Could not find node with id"):
+    await client.get(kind="NetworkDevice", id="missing")
+```
+
+## Fixtures and helpers
+
+- Shared fixtures live in the nearest `conftest.py` to the tests that use them.
+- JSON/YAML test data belongs in `tests/fixtures/` and is loaded via `read_fixture()` from `tests/helpers/fixtures.py`.
+- Use `change_directory()` and `temp_repo_and_cd()` from `tests/helpers/utils.py` for filesystem-dependent tests.
+- Do not duplicate fixture data inline when a fixture file already exists.
+
+## Naming
+
+Do not reference issue numbers, GitHub URLs, or ticket identifiers in test names or docstrings.

docs/CLAUDE.md

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+@AGENTS.md

infrahub_sdk/ctl/CLAUDE.md

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+@AGENTS.md

infrahub_sdk/pytest_plugin/CLAUDE.md

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+@AGENTS.md

tests/CLAUDE.md

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+@AGENTS.md