refactor: flatten monorepo structure to backend/ frontend/ devops/

Rename subdirectories for a cleaner single-repo layout:
- website-monitoring-backend/  → backend/
- website-monitoring-frontend/ → frontend/
- website-monitoring-devops/   → devops/

Update all references in package.json scripts, CI workflows,
docker-compose, pre-commit hooks, and documentation.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/scanner-worker/scan-worker.ts

@@ -0,0 +1,94 @@
+import { createClient } from "@supabase/supabase-js";
+import { launch } from "chrome-launcher";
+import lighthouse from "lighthouse";
+import dotenv from "dotenv";
+
+dotenv.config();
+
+const supabase = createClient(
+  process.env.SUPABASE_URL!,
+  process.env.SUPABASE_SERVICE_KEY!,
+);
+
+async function main() {
+  // 1. Hole alle offenen Scans
+  const { data: scans, error: scanError } = await supabase
+    .from("scans")
+    .select("id, page_id")
+    .eq("status", "pending");
+
+  if (scanError) {
+    console.error("Fehler beim Laden der Scans:", scanError);
+    process.exit(1);
+  }
+
+  for (const scan of scans ?? []) {
+    try {
+      // 2. Hole die URL der Seite
+      const { data: page, error: pageError } = await supabase
+        .from("pages")
+        .select("url")
+        .eq("id", scan.page_id)
+        .single();
+
+      if (pageError || !page) {
+        console.error("Fehler beim Laden der Seite:", pageError);
+        continue;
+      }
+
+      // 3. Setze Scan-Status auf "running"
+      await supabase
+        .from("scans")
+        .update({ status: "running" })
+        .eq("id", scan.id);
+
+      // 4. Starte Lighthouse
+      const chrome = await launch({
+        chromeFlags: ["--headless", "--no-sandbox", "--disable-dev-shm-usage"],
+      });
+
+      const runnerResult = await lighthouse(page.url, {
+        port: chrome.port,
+        output: "json",
+        logLevel: "info",
+        onlyCategories: [
+          "performance",
+          "seo",
+          "accessibility",
+          "best-practices",
+        ],
+      });
+
+      await chrome.kill();
+
+      if (!runnerResult) throw new Error("Lighthouse returned no result");
+
+      // 5. Speichere Ergebnisse
+      await supabase.from("scan_results").insert([
+        {
+          scan_id: scan.id,
+          raw_data: runnerResult.lhr,
+        },
+      ]);
+
+      // 6. Setze Scan-Status auf "completed"
+      await supabase
+        .from("scans")
+        .update({ status: "completed" })
+        .eq("id", scan.id);
+
+      console.log(`Scan für ${page.url} abgeschlossen.`);
+    } catch (error) {
+      console.error("Scan-Fehler:", error);
+      await supabase
+        .from("scans")
+        .update({
+          status: "failed",
+          error_message: error instanceof Error ? error.message : String(error),
+        })
+        .eq("id", scan.id);
+    }
+  }
+}
+
+main();