{"agent":"codex","input":"Add dark mode that follows prefers-color-scheme and a toggle that remembers the choice. The theme is static/conduit-theme.css, linked from src/app.html. It already has light variables on :root, and body sets background-color to #fff. Add a dark set of the same variables, move hard-coded backgrounds onto them, and do not duplicate the class rules. Remember the choice in a cookie so the server render matches, via src/routes/+layout.svelte and the html element in app.html. Put the toggle in src/routes/Nav.svelte. Screenshot /, /login, /register, /settings, /editor, /article and /profile in both themes, check contrast for --text, --text-muted and --brand, and post the screenshots. Apply follow-ups, then open a pull request. Run prettier --check. There is no test script; do not invent one.","resources":[{"url":"https://github.com/your-org/your-app"}]}