Migrate airflow-ai-sdk to apache-airflow-providers-common-ai

This skill migrates Airflow projects from airflow-ai-sdk to apache-airflow-providers-common-ai (0.1.0+), the official Airflow AI provider built on PydanticAI.

CRITICAL: The new provider requires Airflow 3.0+ and pydantic-ai-slim >= 1.34.0. The API surface has changed: LLM configuration moves from code (model strings/objects) to Airflow connections (pydanticai type). There is no @task.embed in the new provider.

Before starting

Use the Grep tool with the pattern below to inventory everything that needs to migrate:

airflow_ai_sdk|airflow-ai-sdk|ai_sdk|@task\.llm|@task\.agent|@task\.llm_branch|@task\.embed

From the results, capture:

1. All files importing airflow-ai-sdk / airflow_ai_sdk
2. Which decorators are in use: @task.llm, @task.agent, @task.llm_branch, @task.embed
3. The model configuration pattern (string names like "gpt-5", or OpenAIModel(...) objects)