feat: add Tool Resolution extension

[SamMorrowDrums]

Summary

• adapt SEP-1862 from a proposed core method into the negotiated io.modelcontextprotocol/tool-resolution extension
• add tools/resolve with per-tool opt-in through namespaced Tool._meta, modern per-request capability negotiation, and legacy initialize compatibility
• return a dedicated metadata-only result with complete argument-specific ToolAnnotations, while retaining tools/list as the authority for identity and schemas
• define conservative static fallback, validation, errors, trust boundaries, side-effect prohibition, TOCTOU limits, and no-cache semantics
• add TypeScript types and reference helpers, generated JSON Schema/type docs, examples, conformance tests, and CI

Review concern addressed

The result deliberately does not return a replacement Tool. This prevents resolution from changing inputSchema, outputSchema, identity, descriptions, titles, or icons after the client has already selected arguments—the major concern raised during SEP-1862 review.

Fallback

Clients that do not negotiate the extension, skip resolution, or encounter a non-argument resolution failure continue using the core tool with its conservative static annotations. Invalid arguments are surfaced and must not be executed unchanged.

Validation

• npm run check
• npm run build
• git diff --check