Add tests for adapter-claude and mcp-server packages

[skokaina]

Problem

packages/adapter-claude/ and packages/mcp-server/ are core features (code generation and IDE integration) with zero test files. Both have vitest configured in package.json but no actual tests.

An HN reviewer running find . -name '*.test.*' will notice immediately.

Scope

adapter-claude

• loadSkill(framework) — test that it loads the correct .md file and prepends guidelines.md
• listFrameworks() — test that it returns sorted array excluding guidelines.md
• buildContext(manifest) — test that $file: refs are resolved and included
• generateWithClaude() — mock the Anthropic API, verify prompt structure and file parsing

mcp-server

• Tool registration — verify all MCP tools are registered
• agentspec_health tool — mock sidecar, verify response shape
• agentspec_gap tool — mock sidecar, verify response shape
• Error handling — sidecar unreachable, invalid responses

Acceptance criteria

• adapter-claude has >=5 unit tests covering core functions
• mcp-server has >=5 unit tests covering tool registration and responses
• Both packages pass pnpm test