AIGRA 0.1.0

Initial development release

• Added R interface for AIGRA: Agentic Item Generation, Review, and Analysis.
• Added support for connecting to a Python backend through reticulate.
• Added PDF parsing workflow for source assessment items.
• Added CSV and Excel item-bank templates.
• Added CSV and Excel item-bank validation.
• Added CSV and Excel item-bank parsing.
• Added item generation workflows for PDF and tabular item banks.
• Added multi-provider text model support for Gemini, OpenAI, Groq, and Anthropic.
• Added multimodal diagram generation support.
• Added multi-model image generation support for Gemini and OpenAI image models.
• Added functions for quality summaries, plots, and HTML reports.
• Added CRAN-safe bundled example item bank.
• Added portable backend-path configuration through AIGRA_BACKEND_PATH.