Code Review

This pull request significantly enhances prompt management by introducing lazy-loaded, file-based prompts and a new prompt method in the Genkit class. Key changes include adding functions to load prompts, partials, and helpers from .prompt files, which register both PROMPT (returning GenerateRequest) and EXECUTABLE_PROMPT (returning GenerateActionOptions) actions. The ExecutablePrompt class gains an as_tool method to expose prompts as actions and a to_generate_request utility function is added. Docstrings were removed from define_indexer and inline imports of GenkitError were introduced, which were noted in review comments. Additionally, the review highlighted a potential AttributeError in as_tool due to commented-out internal attributes and a strong circular reference in prompt action registration that could lead to memory leaks, suggesting the use of weakref. Dependency updates in uv.lock were also made to support opentelemetry-exporter-gcp-monitoring and adjust grpcio versions for Python 3.14+.