Add a vertical slice of real libuv integration by introducing a "timer" CLI module with a Timer class and static sleep() method. This required significant infrastructure changes: setting up libuv event loop in the CLI, creating a new src/module directory for CLI modules, updating all build scripts (Makefile, wren.mk, Xcode project) to handle the new module compilation, and reorganizing CLI code by moving REPL logic from main.c to vm.c. The generate_builtins.py script was also updated to support copying Wren sources into the module directory.
Add a new test framework for exercising the Wren C embedding API directly from C code, including a Makefile target, test runner modifications, and the first API test case for boolean return values. The build system now compiles test sources from `test/api/` into a separate test executable, and the CLI's `createVM` and `runFile` functions accept an optional `WrenBindForeignMethodFn` callback to enable foreign method binding in tests. The test runner (`script/test.py`) is refactored to support both script and API test types, passing the test name instead of the full path for API tests. The initial `return_bool` test verifies that `wrenReturnBool` correctly returns `true` and `false` from foreign methods.
Move runFile() and VM configuration logic from main.c into new vm.c module,
exposing createVM() and runFile() functions. This decouples CLI script
execution from the REPL and main entry point, enabling reuse of the same
VM setup and file-running code for API tests.
