Generates typed Phoenix endpoint helpers from the router.

Emits routes.ts -- typed builders for the server endpoints the frontend calls directly. Which routes qualify is governed by the configured path prefixes (default /shapes and /api):

config :phoenix_assets,
  endpoint_prefixes: ["/api", "/shapes", "/webhooks"]

It deliberately does not generate page routes: in a SvelteKit app the page-route authority is the frontend, so only the Phoenix-owned endpoints belong in a generated contract.

Each route becomes a function keyed by its controller action (or route helper), taking its path parameters and returning the URL with parameters URL-encoded. When two routes share an action name, the later one is qualified with its controller (articleIndex); a numeric suffix is the last resort. Output is sorted by name for deterministic diffs.

Example output

export const routes = {
  articleBySlug: (slug: string | number) =>
    `/shapes/articles/${encodeURIComponent(String(slug))}`,
  health: () => "/api/health",
  publicArticles: () => "/shapes/articles",
} as const