Update Documentation for Gemini Integration

[Olbrasoft]

Parent Issue

#595

Description

Update project documentation to reflect Gemini CLI integration and agent-specific voice support.

Files to Update

1. CLAUDE.md

Add Gemini to agents section:

### Supported Agents

| Agent | Voice | Provider | ID |
|-------|-------|----------|-----|
| claude-code | Antonín (male) | Azure | 4 |
| opencode | Antonín (male) | Azure | 1 |
| gemini | Vlasta (female) | Azure | 11 |

2. README.md

Update architecture diagram and agent list:

• Add Gemini CLI to system diagram
• Document voice differentiation feature
• Add example curl command for Gemini

3. AGENTS.md (if exists)

Update agent documentation with Gemini specifics.

Acceptance Criteria

• CLAUDE.md updated with Gemini information
• README.md architecture diagram includes Gemini CLI
• Voice differentiation feature documented
• Example commands include Gemini
• AgentType enum documented
• Changes committed to feature branch
• Pull request created
• Code review completed
• PR merged to main

Implementation Notes

• Keep documentation style consistent with existing format
• Include code examples where relevant
• Document the enum-based agent system
• Explain voice selection mechanism

Testing

• Documentation renders correctly on GitHub
• All links work
• Code examples are valid