Improve Google Gemini model display names in UI

[ctroche99]

Summary

This PR improves the user experience by displaying clean, human-friendly model names in the UI instead of raw model IDs with prefixes.

Key Changes

• Removed "Google Gemini: " prefix from the pipe name to allow the UI to display only the formatted model name
• Added _format_model_name() method that transforms raw model IDs into readable display names:
  • Converts hyphens to spaces
  • Capitalizes words appropriately
  • Uppercases known acronyms (TTS, AI, HD, SD, 4K, etc.)
  • Preserves version numbers and numeric tokens as-is
  • Examples: gemini-3.1-pro-preview → Gemini 3.1 Pro Preview, veo-3.1-generate → Veo 3.1 Generate
• Updated model listing to use the new formatting method instead of relying on the API's display_name field
• Applied changes consistently across both the __init__ method and the pipes property

Implementation Details

The _format_model_name() method intelligently handles different token types:

• Pure numeric/version tokens (e.g., "3.1", "001") are preserved unchanged
• Known acronyms are fully uppercased for better readability
• All other words are capitalized
• Empty tokens from consecutive hyphens are filtered out
• Falls back to the original model ID if no valid tokens are found

https://claude.ai/code/session_01HJ69Q3sp3yibgFKZTNEbgD