feat: add kokoro plugin

[twilso24]

Plugin: Kokoro TTS

Full control over Kokoro text-to-speech — voice selection, weighted blending, speed adjustment, and language configuration from the Agent Zero settings UI.

• GitHub: https://github.com/twilso24/kokoro-a0-plugin
• Tags: tts, speech, audio, voices

Features

• 10 built-in voices across American and British English
• Weighted voice blending with adjustable weights
• Speed control (0.5x to 3.0x)
• 9 language codes for pronunciation
• Settings UI integrated into Agent Zero speech panel
• Blend files cached and reused across sessions

Security

• Path traversal prevention on voice file operations
• Voice ID validation (built-in IDs only)
• No secrets or credentials stored
• 24 dependency-free unit tests all passing

[3clyp50]

Hi @twilso24, I'm closing this PR because yesterday I've integrated the enhancements into the core of Agent Zero directly in the _kokoro_tts plugin.

Thanks for the contribution,
Alessandro