InferenceOperationType.value casing inconsistent with OTel GenAI semantic conventions

从 libraries/microsoft-agents-a365-observability-core/microsoft_agents_a365/observability/core/inference_operation_type.py 开始，跟踪其值如何通过 InferenceScope 到达 gen_ai.operation.name。比较 Agent365-Samples PR #288 中描述的手动和自动 instrumentation 入口点。完成的标准是：手动 instrumentation 发出的操作名称与自动 instrumentation 发出的相同且均为小写，同时考虑兼容性影响。

Issue

The InferenceOperationType enum in libraries/microsoft-agents-a365-observability-core/microsoft_agents_a365/observability/core/inference_operation_type.py uses capitalized values (Chat, TextCompletion, GenerateContent). These values flow into gen_ai.operation.name span attributes via InferenceScope (manual instrumentation).

The OpenTelemetry GenAI semantic conventions specify lowercase for gen_ai.operation.name values (e.g., chat, text_completion, embeddings). The auto-instrumentation extension packages (e.g., microsoft-agents-a365-observability-extensions-openai) correctly emit lowercase values.

Effect

Customers using manual instrumentation see gen_ai.operation.name="Chat", customers using auto instrumentation see gen_ai.operation.name="chat" for the same operation. Backend filters and dashboards built around one casing won't match spans produced by the other.

Repro

End-to-end run of the two samples in microsoft/Agent365-Samples PR #288:

• python/observability-with-otlp/main.py (manual instrumentation): emits gen_ai.operation.name="Chat", span name Chat gpt-4o-mini
• python/observability-with-azure-monitor/main.py (auto-instrumentation): emits gen_ai.operation.name="chat", span name chat gpt-4.1

Suggested fix

Change InferenceOperationType values to lowercase to match the OTel spec and auto-instrumentation behavior:

```python
class InferenceOperationType(Enum):
CHAT = "chat"
TEXT_COMPLETION = "text_completion"
GENERATE_CONTENT = "generate_content"
```

This is a behavior change — backend dashboards filtering by Chat would stop matching. May need a major-version bump or a transitional period.

Related

• PR #288 in Agent365-Samples documents the discrepancy in the sample READMEs
• Companion docs PR (forthcoming) on Agent365-python documents it in the integration guide

🤖 Filed via Claude Code while validating samples