fastmcp-v3-migration

Production-ready migration from FastMCP v2.x to v3.0. Use when upgrading MCP servers built on FastMCP to v3, migrating legacy FastMCP code, converting v2 patterns to v3 architecture (providers/transforms), or when a user mentions FastMCP upgrade, migration, or v3. Covers breaking changes, deprecated patterns, new v3 features (providers, transforms, versioning, authorization), and testing strategies. Ensures zero-regression migrations with user-confirmation checkpoints.