Replace engine._model/engine._generation_config mocks with
engine._client/engine._model_name. Update sys.modules patches
from vertexai to google.genai. Remove dead if-False branch.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add standalone GeminiEngine class for maintenance schedule extraction
from PDF owners manuals using Vertex AI Gemini 2.5 Flash with structured
JSON output enforcement, 20MB size limit, and lazy initialization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>