chore(ts-sdk): add description to JSR package settings

[rrrodzilla]

JSR Score Issue

The @govcraft/emergent package is missing a description in the JSR package settings.

Current JSR score impact: 0/1 on "Has a description"

Fix

Add a description in the JSR package settings page at https://jsr.io/@govcraft/emergent/settings. Something like:

TypeScript SDK for the Emergent event-driven workflow engine — build Sources, Handlers, and Sinks that connect via Unix IPC.

This is a settings-only change, not a code change.