feat: port pydantic-ai v1.89.1 — bundled Library Skills

[Copilot]

Ports the primary change from pydantic-ai v1.89.1: bundled coding-agent skill files shipped alongside the package for IDE/AI assistant auto-discovery.

What changed

• New: packages/sdk/.agents/skills/building-vibes-agents/ — TypeScript equivalent of pydantic-ai's .agents/skills/building-pydantic-ai-agents/ directory:

  • SKILL.md — entry point with quick-start examples, routing table, and common gotchas
  • references/AGENTS-CORE.md — agent creation, models, output types, run methods, dependency injection
  • references/TOOLS-CORE.md — tool vs plainTool, Zod parameters, argsValidator, retries, fromSchema
  • references/TOOLSETS.md — FunctionToolset, FilteredToolset, WrapperToolset, MCP, lifecycle hooks
  • references/STRUCTURED-OUTPUT.md — Zod output schemas, result validators, outputTool, union types
  • references/TESTING-AND-DEBUGGING.md — TestModel, FunctionModel, captureRunMessages, agent.override()
  • references/MESSAGE-HISTORY-AND-STREAMING.md — history, streaming, typed event stream, eventStreamHandler
  • references/MULTI-AGENT-AND-GRAPH.md — agent-as-tool, sequential handoff, Graph, persistence

• packages/sdk/docs/reference/features.mdx — added Bundled Library Skill row (v1.89.1, ✅)

• .github/pydantic-ai-version.txt — bumped to 1.89.1

Not ported

Change	Reason
Bug fix: wrap_validation_errors on ToolManager	Python-only ToolManager/capabilities hook chain; vibes uses direct tool execution
Defer anyio.Lock creation	Python-specific async event loop binding