fix: make build tooling paths portable

[KirtiRamchandani]

Problem

Some repo build and test tooling assumes POSIX shell/path behavior. On Windows, that can break before the intended command runs:

• prebuild uses rm -rf build.
• Several scripts convert import.meta.url with new URL(...).pathname, which produces invalid filesystem paths for Windows drive-letter paths.
• test:circular relies on shell glob expansion for src/*.

Root cause

URL pathnames are not filesystem paths on all platforms, and npm scripts should not depend on shell-specific cleanup or glob expansion for these commands.

Solution

• Use fileURLToPath(import.meta.url) before passing module paths to node:path.
• Replace the prebuild cleanup with fs.rmSync(..., { recursive: true, force: true }) through Node.
• Run Madge against the src directory with explicit TypeScript extensions.
• Keep the architecture script reference in sync with package.json.

Tests

• npm run build:versions
• npm run test:license
• npm run test:circular
• npm run test:size
• node --check on modified scripts/tests
• npx prettier --check package.json docs\architecture.md scripts\build-js.mjs scripts\build-jsr.mjs scripts\build-pkgjson-lite.mjs scripts\build-pkgjson-main.mjs scripts\build-size-limit.mjs scripts\build-tests.mjs scripts\build-versions.mjs test\extra.test.js test\it\build-jsr.test.js
• git diff --check