feat: add error and log span kinds

[Br1an67]

📥 Pull Request

📘 Description

Add ERROR and LOG span kinds to the SDK, addressing both #1025 and #1024.

Each span kind is available in two forms:

Decorators — wrap functions to trace them as error/log spans:

from agentops.sdk.decorators import error, log

@error
def handle_failure():
    ...

@log(name="custom_log")
def log_event():
    ...

Standalone functions — create one-shot event spans:

import agentops

agentops.error(name="validation_failed", message="Invalid input format")
agentops.log(name="checkpoint", message="Processing complete", level="INFO")

Changes:

• agentops/semconv/span_kinds.py: Add ERROR and LOG to AgentOpsSpanKindValues enum and SpanKind class
• agentops/sdk/decorators/__init__.py: Create error/log decorators via create_entity_decorator factory
• agentops/__init__.py: Add standalone error() and log() functions using _create_as_current_span, update exports

🧪 Testing

Added 14 unit tests in tests/unit/sdk/test_error_log_spans.py covering:

• Error decorator: basic span creation, custom name, async support
• Log decorator: basic span creation, custom name
• Standalone error(): span creation, error status code, extra attributes, default name
• Standalone log(): span creation, log level, default INFO level, extra attributes, default name

All 164 tests pass (including existing tests). Ruff lint clean.