feat: enable video uploads for Gemini 2.5 Pro models

[roomote]

This PR enables video upload support for Gemini 2.5 Pro and Flash models in Roo Code.

Changes

• Added supportsVideo property to the ModelInfo schema
• Marked Gemini 2.5 Flash and all Gemini 2.5 Pro model variants as supporting video
• Updated ChatTextArea component to accept video files (mp4, mov, avi, webm) when the selected model supports video
• Video files are handled through the existing image upload mechanism, as Gemini API accepts both images and videos through the same inlineData format

Implementation Details

• The supportsVideo property is optional and defaults to false for backward compatibility
• Video support is conditionally enabled based on the selected model
• Supported video formats: MP4, MOV, AVI, WebM
• No changes were needed to the Gemini format transformer as it already handles videos correctly

Fixes #6144

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Important

Adds video upload support for Gemini 2.5 Pro and Flash models by introducing a supportsVideo property and updating UI components to handle video files.

• Behavior:
  • Adds supportsVideo property to modelInfoSchema in model.ts, defaulting to false for backward compatibility.
  • Enables video upload for Gemini 2.5 Pro and Flash models in gemini.ts by setting supportsVideo to true.
  • Updates ChatTextArea in ChatTextArea.tsx to accept video files (mp4, mov, avi, webm) if the model supports video.
  • Video files are processed through the existing image upload mechanism.
• UI Components:
  • Modifies ChatTextArea and ChatView to handle video file selection and upload.
  • Adds supportsVideo prop to ChatTextArea to conditionally allow video uploads.
• Misc:
  • No changes to the Gemini format transformer as it already supports videos.

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[daniel-lxs]

Closing in favor of #6150, it seems to have a more complete implementation