API evolution and migration

The v0.1.1 @pumpkinmc/pumpkin-api-ts API is the compatibility baseline. The migration guide covers the package and build changes. The full compatibility inventory records the decision for every export, type, WIT declaration and operation. Facade behavior changes include command-suggestion errors reporting the requested handler ID, IPC rejection paths throwing descriptive Error objects, callback cleanup after unload or failed registration, and rejecting task tick values other than numbers or bigints at runtime. The migration guide describes their impact.

Replace imports from @pumpkinmc/pumpkin-api-ts with @pumpkin-plugins/pumpkin-api, add the new package as a runtime dependency, and use pumpkin-plugins-build from @pumpkin-plugins/build to build components and generate types. No old package or build-command alias is provided.

Before 1.0.0, compatible fixes use patch versions; features and breaking changes use the next minor version, so a breaking change from 0.1.0 becomes 0.2.0. Starting at 1.0.0, breaking changes require a major version. Breaking commits use a Conventional Commit ! marker or BREAKING CHANGE footer and include release notes plus migration steps.