fix: emit cache hints from handler macros

[DaleSeo]

Fixes #1114

Motivation and Context

Strict clients using protocol version 2026-07-28 reject list responses that don't include ttlMs and cacheScope. As a result, servers using the documented handler macros don't work until the first tool or prompt call. This PR fixes that by adding immediately stale public cache hints for modern clients while continuing to omit them for legacy clients. With this fix macro-generated tools/list and prompts/list responses include the cache hints required by clients that negotiate protocol version 2026-07-28. Older clients still receive the same legacy wire format.

How Has This Been Tested?

Added integration tests

Breaking Changes

None. The new fields are emitted only where the negotiated protocol requires them.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed