## Problem The `AiModelCapability` enum in `web/modules/custom/ai/src/Enum/AiModelCapability.php` exposes chat input modality capabilities for image, audio, and video, but lacks a case for PDF input. Several providers (e.g. Anthropic, Google Gemini, OpenAI) support passing PDF documents directly into chat tools, and there is currently no way for a provider plugin to advertise that capability or for consumers to require it. ## Proposed solution Add a new case to `AiModelCapability`: - `ChatWithPdf = 'chat_with_pdf'` Wire it into the three `match` arms: - `getBaseOperationType()` → `'chat'` - `getTitle()` → `'Chat with PDF'` - `getDescription()` → `'Is set if the chat model can include PDF documents in the chat input.'` ## Scope Enum addition only. Provider plugins that support PDF input can opt in to the new capability separately.