feat: support event checklists

[seisyo58]

Summary

• Add checklist support to event create/update operations
• Include checklist in event list/update response payloads
• Add TimeTree attachment/checklist types

Test plan

• npm run build
• hermes mcp test timetree
• Manual test against a real TimeTree calendar through Hermes MCP:
  • Create an event without checklist
  • Add checklist to an existing event
  • Update checklist items to checked: true
  • Update checklist items back to checked: false
  • Remove checklist by setting checklist: []
  • Delete the event
  • Create an event with checklist

The create/update responses returned checklist as expected.

[ehs208]

Thanks for the contribution! This is a great addition — checklist support is something users will definitely find useful, and the implementation is clean.

One small suggestion: could you add a mention of checklist support in the description string of create_event and update_event tools? AI clients rely on the tool description to decide which tool to invoke, so without it, a user saying "add a checklist to my event" might not trigger the right tool.

Something like appending "Supports attaching checklist items." to the existing description would be enough.

[seisyo58]

Thanks! Updated the tool descriptions to mention support for attaching checklist items.

[ehs208]

Looks great, thanks for the first contribution! Merging now.