Add Google Gemini AI provider support

[Sumit6307]

This PR adds a new GeminiProvider to the Joomla AI Framework.

• Implements Chat and Model capabilities
• Uses the existing provider architecture
• Enables Google Gemini as a pluggable AI backend

[Hackwar]

Contrary to what was stated, this PR does not close issue #11.

[Sumit6307]

Contrary to what was stated, this PR does not close issue #11.

@Hackwar
Thanks for the clarification. You’re right — this PR does not close issue #11.

This PR is scoped specifically to adding Google Gemini AI provider support to the Joomla AI Framework. It introduces a new GeminiProvider with chat and model capabilities using the existing provider architecture.

It was not intended to address or close issue #11. I’ll update the description if needed to avoid confusion.

[Sumit6307]

Contrary to what was stated, this PR does not close issue #11.

@Hackwar
Thanks for the clarification. You’re right — this PR does not close issue #11.

This PR is scoped specifically to adding Google Gemini AI provider support to the Joomla AI Framework. It introduces a new GeminiProvider with chat and model capabilities using the existing provider architecture.

It was not intended to address or close issue #11. I’ll update the description if needed to avoid confusion.