Add CrewAI, OpenAI Agents SDK, AutoGen, and FastAPI adapters

[Sunny-commit]

Goal

Let developers add OpenDecision to common agent stacks with minimal integration code.

Scope

• CrewAI tool guard/decorator adapter.
• OpenAI Agents SDK tool-call middleware.
• AutoGen tool-call wrapper.
• FastAPI middleware or dependency pattern for request/action gates.

Acceptance criteria

• Framework-specific code stays outside the core package.
• Dependencies are optional and lazy.
• Each adapter has a minimal executable example and contract tests.
• Errors, review outcomes, sync/async behavior, and cancellation are documented.
• No adapter bypasses framework authorization or confirmation semantics.

Sequencing

Implement one adapter per focused pull request.