feat: add FuturMix as AI model provider

[FuturMix]

Summary

Add FuturMix as a new AI provider in bolt.diy. FuturMix is an enterprise AI agent platform providing 22+ models .

Changes

• Add app/lib/modules/llm/providers/futurmix.ts — Provider implementation
• Update app/lib/modules/llm/registry.ts — Register provider
• Update .env.example — Add FUTURMIX_API_KEY variable

Features

• Static models: Claude 4 Opus, Claude Sonnet 4.5, GPT-4o, Gemini 2.5 Pro/Flash, DeepSeek
• Dynamic model discovery via /v1/models endpoint
• Uses getOpenAILikeModel() for OpenAI compatibility
• 99.99% SLA with auto-failover

Configuration

Set FUTURMIX_API_KEY in environment or enter in the UI provider settings.

Test Plan

• Provider appears in model selector
• Models load correctly (static + dynamic)
• Chat completions work with FuturMix API key

🤖 Generated with Claude Code