BREAKING CHANGE(tapbundle_serverside): Rename Node-specific tapbundle module to tapbundle_serverside and migrate server-side utilities

readme.md

@@ -318,9 +318,34 @@ tstest provides multiple exports for different use cases:
 
 - `@git.zone/tstest` - Main CLI and test runner functionality
 - `@git.zone/tstest/tapbundle` - Browser-compatible test framework
-- `@git.zone/tstest/tapbundle_node` - Node.js-specific test utilities
+- `@git.zone/tstest/tapbundle_serverside` - Server-side testing utilities for Node.js-only tests (*.node.ts files)
+  - Execute shell commands during tests
+  - Manage environment variables on-demand with secure storage
+  - Generate self-signed HTTPS certificates for testing secure connections
+  - Create ephemeral MongoDB instances for database testing
+  - Create local S3-compatible storage for object storage testing
+  - Download and manage test assets (e.g., Docker images)
 - `@git.zone/tstest/tapbundle_protocol` - Protocol V2 emitter and parser for TAP extensions
 
+### When to Use tapbundle_serverside
+
+Use `@git.zone/tstest/tapbundle_serverside` when your tests:
+
+- Run exclusively on Node.js server-side (*.node.ts test files)
+- Need to execute shell commands or interact with the file system
+- Require environment variable management with secure on-demand prompts
+- Test HTTPS servers and need self-signed certificates
+- Interact with databases (MongoDB) and need ephemeral test instances
+- Work with object storage (S3-compatible) and need local testing
+- Require test assets like Docker images or other downloadable files
+
+**Important:** tapbundle_serverside utilities are NOT available in:
+- Browser environments
+- Deno runtime
+- Bun runtime
+
+For cross-runtime tests, only import tapbundle_serverside in `.node.ts` files where you need server-side specific functionality.
+
 ## tapbundle Protocol V2
 
 tstest includes an enhanced TAP protocol (Protocol V2) that extends standard TAP 13 with additional metadata while maintaining backwards compatibility.