fix: record auditlog ng telemetry on client initialization

[tiagoek]

Disclaimer: Do not include SAP-internal or customer-specific information in this PR (e.g. internal system URLs, customer names, tenant IDs, or confidential configurations). This is a public repository.

Description

Moves the ALS v3 (auditlog_ng) AUDITLOG_CREATE_CLIENT capability metric from the public factory wrapper to the shared AuditClient initialization path. This keeps the signal as client/capability initialization rather than audit-event volume, while ensuring direct AuditClient(config) construction emits the same SDK usage telemetry as create_client(config=...).

The factory still records error metrics for validation/configuration failures that happen before AuditClient can be initialized, preserving the previous error telemetry behavior. The package version is bumped to 0.20.2.

Related Issue

Internal tracking: AFSDK-3392

Type of Change

Please check the relevant option:

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Code refactoring
• Dependency update

How to Test

1. Run focused telemetry and auditlog NG tests:
   uv run pytest tests/core/unit/test_version.py tests/core/unit/auditlog_ng/unit/test_create_client.py tests/core/unit/auditlog_ng/unit/test_client.py tests/core/unit/telemetry/test_metrics_decorator.py -q
2. Run non-integration unit tests:
   uv run pytest tests -m 'not integration' -q
3. Run lint/type/build checks:
   uv run ruff check pyproject.toml src/sap_cloud_sdk/core/auditlog_ng/__init__.py src/sap_cloud_sdk/core/auditlog_ng/client.py src/sap_cloud_sdk/core/telemetry/metrics_decorator.py tests/core/unit/auditlog_ng/unit/test_create_client.py tests/core/unit/auditlog_ng/unit/test_client.py tests/core/unit/telemetry/test_metrics_decorator.py
uv run ty check
uv build
4. Run integration checks with configured service bindings:
   uv run pytest tests/core/integration/auditlog -q
uv run pytest tests -m integration --ignore=tests/destination/integration -q

Expected result: direct AuditClient(config) and factory-created clients both record exactly one auditlog_ng/create_client capability metric on successful initialization, without instrumenting send() or send_json().

Checklist

Before submitting your PR, please review and check the following:

• I have read the Contributing Guidelines
• I have verified that my changes solve the issue
• I have added/updated automated tests to cover my changes
• All tests pass locally
• I have verified that my code follows the Code Guidelines
• I have updated documentation (if applicable)
• I have added type hints for all public APIs
• My code does not contain sensitive information (credentials, tokens, etc.)
• I have followed Conventional Commits for commit messages

Breaking Changes

None.

Additional Notes

send() and send_json() remain uninstrumented intentionally. The dashboard signal should represent ALS v3 capability/client initialization, not audit event volume.

Local verification performed:

• 53 passed for focused version/auditlog NG/telemetry tests.
• 2098 passed, 125 deselected for non-integration tests.
• 21 passed for AuditLog integration tests with configured bindings.
• 65 passed, 31 skipped for integration tests excluding Destination.
• uv run ty check completed with only pre-existing DMS integration warnings.
• uv build produced sap_cloud_sdk-0.20.2 sdist and wheel.

Full integration was also executed; remaining failures were limited to known Destination integration scenarios and are unrelated to ALS v3 telemetry.

[jeanscherf]

Great work!