Add fastmcp skill for Python MCP server development

[sharanharsoor]

FastMCP is the standard Python framework for building MCP servers. This skill teaches production patterns verified against FastMCP 3.2.x, specifically addressing APIs that LLMs hallucinate (server.state, on_startup, context.name in middleware — none of which exist).

Detection: 'fastmcp' pattern in pyproject.toml/requirements.txt
Validation: 97.1% (agentskills.io spec checker)

What Changed

• Added fastmcp entry to skills-map.ts with detection via pyproject.toml / requirements.txt patterns
• Added packages/autoskills/skills-registry/fastmcp/SKILL.md with production patterns

Why This Change

FastMCP is Python's standard framework for building MCP servers (~10k weekly downloads). Currently no FastMCP skill exists in autoskills. LLMs hallucinate FastMCP APIs regularly — this skill fixes the three most common ones:

• server.state.pool = ... → AttributeError (server.state does not exist)
• @mcp.on_startup → AttributeError (does not exist in v2+)
• context.name in middleware → AttributeError (correct: context.message.name)

Skill covers: lifespan/startup patterns, middleware, multi-operation tools, output formatting, partial failure handling, testing with fastmcp.Client, and common mistakes.

Testing Done

• Manual testing completed — npx skills add sharanharsoor/skills installs correctly across 14 agent tools
• Automated tests pass locally — 42 code pattern tests against real FastMCP 3.2.2, 8/8 routing evals pass
• Edge cases considered — negative routing (general MCP questions do NOT activate this skill)

Type of Change

• feat: New feature

Security & Quality Checklist

• No secrets or API keys committed
• Follows the project's coding standards
• No sensitive data exposed in logs or output

Documentation

• README not applicable (new skill addition)
• SKILL.md is self-documenting with When to use, Common Mistakes, and Testing reference
• Skill published at https://skills.sh/sharanharsoor/skills/fastmcp