S03: Consistent site origin — trailingSlash never, canonical URLs

- Add trailingSlash: 'never' to Astro config
- Normalize sitemap paths to never use trailing slash
- Ensures consistent canonical URLs across all pages
- Prevents duplicate content from / vs /path/ variants

apps/web/astro.config.mjs

@@ -3,6 +3,7 @@ import node from "@astrojs/node";
 
 export default defineConfig({
   site: process.env.PUBLIC_SITE_URL || "https://rf4spotter.ru",
+  trailingSlash: "never",
   output: "server",
   adapter: node({ mode: "standalone" }),
   server: { host: true, port: 4321 },

apps/web/src/pages/sitemap.xml.ts

@@ -24,7 +24,9 @@ export const GET: APIRoute = async ({ site }) => {
       if (paths.size > 49000) throw new Error("Sitemap index required");
       if (rows.length < 1000) break;
     }
-    const xml = `<?xml version="1.0" encoding="UTF-8"?><urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">${[...paths].map(path => `<url><loc>${escapeXml(new URL(path, origin).toString())}</loc></url>`).join("")}</urlset>`;
+    // Normalize paths: never use trailing slash (S03)
+    const normalized = [...paths].map(p => p.replace(/\/$/, "") || "/");
+    const xml = `<?xml version="1.0" encoding="UTF-8"?><urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">${normalized.map(path => `<url><loc>${escapeXml(new URL(path, origin).toString())}</loc></url>`).join("")}</urlset>`;
     lastGood = { origin, xml, at: Date.now() };
     return output(xml);
   } catch {