🎞️ feat: OpenRouter Audio/Video File Upload Support (#11070)

* Added video upload support for OpenRouter

- Added VIDEO_URL content type to support video_url message format
- Implemented OpenRouter video encoding using base64 data URLs
- Extended encodeAndFormatVideos() to handle OpenRouter provider
- Updated UI to accept video uploads for OpenRouter (mp4, webm, mpeg, mov)
- Fixed case-sensitivity in provider detection for agents
- Made isDocumentSupportedProvider() and isOpenAILikeProvider() case-insensitive

Videos are now converted to data:video/mp4;base64,... format compatible
with OpenRouter's API requirements per their documentation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

* refactor: change multimodal and google_multimodal to more transparent variable names of image_document and image_document_video_audio

(also google_multimodal doesn't apply as much since we are adding support for video and audio uploads for open router)

* fix: revert .toLowerCase change to isOpenAILikeProvider and isDocumentSupportedProvider which broke upload to provider detection for openAI endpoints

* wip: add audio support to openrouter

* fix: filetypes now properly parsed and sent rather than destructured mimetypes for openrouter

* refactor: Omit to Exclude for ESLint

* feat: update DragDropModal for new openrouter support

* fix: special case openrouter for lower case provider

(currently getting issues with the provider coming in as 'OpenRouter' and our enum being 'openrouter') This will probably require a larger refactor later to handle case insensitivity for all providers, but that will have to be thoroughly tested in its own isolated PR

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
Co-authored-by: Dustin Healy <54083382+dustinhealy@users.noreply.github.com>

client/src/components/Chat/Input/Files/DragDropModal.tsx

@@ -2,6 +2,7 @@ import React, { useMemo } from 'react';
 import { useRecoilValue } from 'recoil';
 import { OGDialog, OGDialogTemplate } from '@librechat/client';
 import {
+  Providers,
   inferMimeType,
   EToolResources,
   EModelEndpoint,
@@ -55,15 +56,21 @@ const DragDropModal = ({ onOptionSelect, setShowModal, files, isVisible }: DragD
 
   const options = useMemo(() => {
     const _options: FileOption[] = [];
-    const currentProvider = provider || endpoint;
+    let currentProvider = provider || endpoint;
+
+    // This will be removed in a future PR to formally normalize Providers comparisons to be case insensitive
+    if (currentProvider?.toLowerCase() === Providers.OPENROUTER) {
+      currentProvider = Providers.OPENROUTER;
+    }
 
     /** Helper to get inferred MIME type for a file */
     const getFileType = (file: File) => inferMimeType(file.name, file.type);
 
     // Check if provider supports document upload
     if (isDocumentSupportedProvider(endpointType) || isDocumentSupportedProvider(currentProvider)) {
-      const isGoogleProvider = currentProvider === EModelEndpoint.google;
-      const validFileTypes = isGoogleProvider
+      const supportsImageDocVideoAudio =
+        currentProvider === EModelEndpoint.google || currentProvider === Providers.OPENROUTER;
+      const validFileTypes = supportsImageDocVideoAudio
         ? files.every((file) => {
             const type = getFileType(file);
             return (