Merge main updates into huggingface-space-deployment

Replace AIOrchestrator with LiteLLM Router for multi-provider fallback

feat: replace Gemini with OpenRouter as fallback AI provider

feat: rebrand FALSA to FALZH with updated supabase schema, tool names, and prompts

feat: replace Hugging Face with Gemini as fallback AI provider

feat: support multiple phone numbers and prevent duplicate customers

first commit