Add Gemini 2.5 Pro and Flash API Bots

[PeterDaveHello]

This commit introduces support for the new Gemini 2.5 Pro and Gemini 2.5 Flash models.

Key changes:

• Added Gemini25ProAPIBot.js and Gemini25FlashAPIBot.js based on existing Gemini bot implementations.
• Registered the new bots in src/bots/index.js, making them available in the API category.
• Included new logo files (gemini-2.5-pro-logo.png and gemini-2.5-flash-logo.png) in public/bots/.
• Updated all localization files under src/i18n/locales/ to include translations for the new models within the geminiApi section.

Summary by CodeRabbit

• New Features
  • Introduced two new Gemini model variants: Gemini 2.5 Pro Preview and Gemini 2.5 Flash Preview, now available for selection.
• Localization
  • Added support for new Gemini model names across multiple languages, including English, German, Spanish, French, Italian, Japanese, Korean, Russian, Vietnamese, Simplified Chinese, and Traditional Chinese.