Reference for netlify.toml configuration and site environment variables. Use when configuring build settings, redirects, rewrites, headers, deploy contexts, the `[dev]` block that controls `netlify dev` (command, port, targetPort, framework), or any site-level configuration — and when managing environment variables or secrets with the Netlify CLI, including scoping values to specific deploy contexts. Covers the complete netlify.toml syntax including redirects with splats/conditions, headers, deploy contexts, functions config, edge functions config, and the `[dev]` block (including when `framework` must be `"#custom"` — required when both a custom `command` and `targetPort` are set).