[AAASM-3435] ✅ (python-sdk): Gate native-core-absent test guards

[Chisanan232]

Description

Three unit tests assumed the native PyO3 _core extension is absent (CI's pure-Python matrix). When _core IS built, they failed:

• test_init_assembly_enforcement_mode_forwarded_to_client[enforce] — monkeypatched adapters/network but not the AAASM-3402 native registration, so enforce fired a real gRPC registration → fail-closed → ConfigurationError.
• test_to_wire_bytes_raises_helpful_import_error_without_native_core / test_from_wire_bytes_... — asserted an ImportError that only occurs when _core is absent (with _core present the wire codec runs).

This PR makes the three tests pass regardless of whether _core is importable. Test-only changes; no product code touched.

• Gated the two wire-codec import-error tests with @pytest.mark.skipif(_native_core_available(), ...) (reusing the codebase's own agent_assembly.core.runtime_interceptor._native_core_available detector) so they only assert the import-error path when _core is genuinely absent.
• Stubbed the native path in the enforce-mode test (monkeypatch.setattr(core_assembly, "_native_core_available", lambda: False)) so it still asserts enforcement-mode forwarding to the client without performing a live gateway connect.

Type of Change

• 🔧 Bug fix

Breaking Changes

• No

Related Issues

• Related JIRA ticket: AAASM-3435

Testing

• Unit tests added/updated

Reproduced with maturin develop (native _core present) on macOS:

• Before: the 3 tests FAILED (gRPC endpoint unreachable for registration; DID NOT RAISE ImportError; invalid tag value: 0).
• After: test/unit/test_assembly.py test/unit/test_types_audit_event.py → 39 passed, 2 skipped (the 3 target tests now pass: enforce-mode forwards for all 3 modes; the two wire-codec guards correctly skip when _core is present). The skipif path still asserts the import-error behavior when _core is absent. ruff format, mypy, and pre-commit run --all-files clean on touched files.

Checklist

• Code follows project style guidelines
• Self-review completed
• All tests passing

Closes AAASM-3435

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Chisanan232]

Claude Code — PR review (AAASM-3435)

Verdict: ✅ ready to merge. CI green; test-only (2 files), no product code touched.

• Reuses the codebase's own _native_core_available detector — correct, no new ad-hoc probing. ✅
• Wire-codec import-error tests now skipif(_native_core_available()) — they only assert the ImportError path when _core is genuinely absent. ✅
• Enforce-mode forwarding test stubs _native_core_available → False so it verifies enforcement-mode forwarding without firing the AAASM-3402 native gRPC registration (which fail-closes without a live gateway). ✅
• Verified RED-before / GREEN-after with _core built: 39 passed, 2 (correctly) skipped.

Pre-existing ARG002/ARG005 ruff warnings on test_assembly.py are from the existing mock pattern on master, not introduced here. Good to merge.