Vite conventions — reading env through `import.meta.env.VITE_*` and why an unprefixed variable arrives undefined in the browser, why `process.env` is not available in client code, declaring the path alias in every tool that resolves modules, and build output. Use when configuring Vite, adding an environment variable, or debugging an import that resolves in the build but not in the test runner or the type checker. Vite-specific — skip if the project uses another bundler.
