Add comprehensive agent framework integration guides

[strawgate]

This PR adds 20 new integration documentation pages covering popular AI agent frameworks and LLM platforms across multiple languages (Python, TypeScript, Go, Rust, .NET).

Summary

Adds extensive documentation for integrating Pydantic Logfire with agent frameworks and LLM platforms. Each guide includes:

• Framework overview and integration approach
• Installation instructions
• Runnable code examples
• Configuration details for sending telemetry to Logfire

New Integration Guides

Python LLM/Agent Frameworks:

• CrewAI — multi-agent orchestration via OpenInference
• Google ADK — native OTel instrumentation
• Semantic Kernel (Python) — native OTel with diagnostics env var
• Instructor — structured outputs with validation tracing
• LangGraph — stateful graphs via LangSmith OTel bridge
• AutoGen — multi-agent via OpenInference
• Haystack — pipeline components via OpenInference
• Agno — multi-agent systems via OpenInference
• smolagents — code-thinking agents via OpenInference
• Strands Agents — native OTel tracer provider
• Letta (formerly MemGPT) — OTLP/gRPC via OpenTelemetry Collector

TypeScript/JavaScript Agent Frameworks:

• OpenAI Agents SDK — custom TracingProcessor bridge to OTel
• Mastra — observability with OTel exporter
• LlamaIndex.TS — OpenLLMetry/Traceloop OTLP integration
• LangChain.js / LangGraph.js — LangSmith OTel exporter
• Vercel AI SDK — built-in OTel support
• VoltAgent — OTel span processors

Go Agent Frameworks:

• Eino — custom callbacks handler with OTLP exporter
• Genkit (Go) — global OTel TracerProvider

Rust Agent Frameworks:

• Rig — Logfire Rust SDK or standard OTel OTLP exporter

.NET Agent Frameworks:

• Semantic Kernel (.NET) — native OTel with OTLP exporter
• Microsoft Agent Framework (.NET) — GenAI semantic conventions

Index Page:

• New docs/integrations/agent-frameworks/index.md — overview of three integration patterns (native OTel, instrumentors, OTLP over wire)

Documentation Updates

• Updated docs/nav.json to include all new integration links organized under "Agent Frameworks" and "LLMs" sections
• Updated docs/integrations/index.md to reference agent frameworks
• Updated docs/languages.md to mention agent framework integrations

Integration Patterns Documented

1. Native OpenTelemetry — frameworks that emit OTel spans through global tracer provider
2. Instrumentors — OpenInference/OpenLLMetry packages that add spans automatically
3. OTLP over the wire — frameworks requiring explicit OTLP exporter configuration

Each guide includes practical code examples, environment variable setup, and notes on framework-specific configuration.

https://claude.ai/code/session_0176U6NDhFtgGhxKLykUHQzU