Add server-side HMR infrastructure
Add server HMR functions to enable hot module replacement for server-side
code in Turbopack:
Rust (crates/next-api/src/project.rs):
- server_hmr_content: Get server module content by identifier
- server_hmr_version: Get server module version
- server_hmr_version_state: Get version state for server HMR session
- server_hmr_update: Compute server HMR update delta
- server_hmr_identifiers: List all server HMR identifiers
NAPI bindings (crates/napi/src/next_api/project.rs):
- project_server_hmr_events: Subscribe to server HMR events
- project_server_hmr_identifiers_subscribe: Subscribe to server identifiers
TypeScript (packages/next/src/build/swc):
- serverHmrEvents(): Subscribe to server HMR events
- serverHmrIdentifiersSubscribe(): Subscribe to server identifiers
Debug test code added to hot-reloader-turbopack.ts to verify the
subscriptions work correctly during development.
