Add search and filters to the scan history (Verlauf) view

Task: Filter and search scans in the history view (Task #32).

What changed:
- artifacts/skillguard/src/pages/scan-history.tsx now has a client-side
  search box that matches scan name and description text (case-insensitive),
  plus two multi-select toggle-group filters: Bewertung (verdict:
  pass/review/block) and Quelle (source: zip/file/text).
- Filtering is computed via useMemo over the existing useListScans() result.
- Added a results counter ("X von Y Scans") and a "Filter zurücksetzen"
  button shown when any filter/search is active.
- Added a dedicated empty-filter-result state ("Keine Treffer") with a
  reset action, distinct from the existing "no scans yet" empty state.
- Search input has a clear (X) button.

Notes / deviations:
- No backend changes; description/verdict/source already come from the API.
- Rebuilt lib/api-client-react declarations (tsc -b) because the dist
  *.d.ts in this isolated env were stale and lacked description/relation
  fields (pre-existing issue, documented in memory). tsc on scan-history
  is now clean.
- Verified visually: search bar, verdict and source filters render and the
  list populates from the running API server.

Replit-Task-Id: 67d3a8ce-f780-4b21-97b4-4767ced763c4

artifacts/skillguard/src/pages/scan-history.tsx

@@ -1,22 +1,63 @@
+import { useMemo, useState } from "react";
 import { Link } from "wouter";
 import { useQueryClient } from "@tanstack/react-query";
 import { useListScans, getListScansQueryKey, useDeleteScan } from "@workspace/api-client-react";
-import { Card, CardContent } from "@/components/ui/card";
+import { Card } from "@/components/ui/card";
 import { Badge } from "@/components/ui/badge";
 import { Skeleton } from "@/components/ui/skeleton";
 import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { ToggleGroup, ToggleGroupItem } from "@/components/ui/toggle-group";
 import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle, AlertDialogTrigger } from "@/components/ui/alert-dialog";
 import { VerdictBadge, RelationBadge } from "@/components/ui-helpers";
 import { formatDate } from "@/lib/format";
-import { Search, Trash2, ArrowRight } from "lucide-react";
+import { Search, Trash2, ArrowRight, X } from "lucide-react";
 import { useToast } from "@/hooks/use-toast";
 
+const VERDICT_OPTIONS = [
+  { value: "pass", label: "Freigabe" },
+  { value: "review", label: "Manuelle Prüfung" },
+  { value: "block", label: "Blockieren" },
+] as const;
+
+const SOURCE_OPTIONS = [
+  { value: "zip", label: "ZIP" },
+  { value: "file", label: "Datei" },
+  { value: "text", label: "Text" },
+] as const;
+
 export default function ScanHistory() {
   const { data: scans, isLoading } = useListScans();
   const queryClient = useQueryClient();
   const deleteScan = useDeleteScan();
   const { toast } = useToast();
 
+  const [query, setQuery] = useState("");
+  const [verdictFilters, setVerdictFilters] = useState<string[]>([]);
+  const [sourceFilters, setSourceFilters] = useState<string[]>([]);
+
+  const hasActiveFilters = query.trim() !== "" || verdictFilters.length > 0 || sourceFilters.length > 0;
+
+  const resetFilters = () => {
+    setQuery("");
+    setVerdictFilters([]);
+    setSourceFilters([]);
+  };
+
+  const filteredScans = useMemo(() => {
+    if (!scans) return [];
+    const q = query.trim().toLowerCase();
+    return scans.filter((scan) => {
+      if (verdictFilters.length > 0 && !verdictFilters.includes(scan.verdict)) return false;
+      if (sourceFilters.length > 0 && !sourceFilters.includes(scan.source)) return false;
+      if (q) {
+        const haystack = `${scan.name ?? ""} ${scan.description ?? ""}`.toLowerCase();
+        if (!haystack.includes(q)) return false;
+      }
+      return true;
+    });
+  }, [scans, query, verdictFilters, sourceFilters]);
+
   const handleDelete = (id: number) => {
     deleteScan.mutate({ id }, {
       onSuccess: () => {
@@ -59,8 +100,87 @@ export default function ScanHistory() {
           </Button>
         </Card>
       ) : (
-        <div className="space-y-4">
+        <>
-          {scans.map((scan) => (
+          <div className="flex flex-col gap-4 lg:flex-row lg:items-center lg:justify-between">
+            <div className="relative w-full lg:max-w-sm">
+              <Search className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-muted-foreground" />
+              <Input
+                value={query}
+                onChange={(e) => setQuery(e.target.value)}
+                placeholder="Nach Name oder Beschreibung suchen…"
+                className="pl-9 pr-9"
+                aria-label="Scans durchsuchen"
+              />
+              {query && (
+                <button
+                  type="button"
+                  onClick={() => setQuery("")}
+                  className="absolute right-2 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
+                  aria-label="Suche löschen"
+                >
+                  <X className="w-4 h-4" />
+                </button>
+              )}
+            </div>
+            <div className="flex flex-wrap items-center gap-4">
+              <div className="flex flex-col gap-1">
+                <span className="text-xs font-medium text-muted-foreground">Bewertung</span>
+                <ToggleGroup
+                  type="multiple"
+                  variant="outline"
+                  size="sm"
+                  value={verdictFilters}
+                  onValueChange={setVerdictFilters}
+                  className="justify-start"
+                >
+                  {VERDICT_OPTIONS.map((opt) => (
+                    <ToggleGroupItem key={opt.value} value={opt.value} aria-label={opt.label}>
+                      {opt.label}
+                    </ToggleGroupItem>
+                  ))}
+                </ToggleGroup>
+              </div>
+              <div className="flex flex-col gap-1">
+                <span className="text-xs font-medium text-muted-foreground">Quelle</span>
+                <ToggleGroup
+                  type="multiple"
+                  variant="outline"
+                  size="sm"
+                  value={sourceFilters}
+                  onValueChange={setSourceFilters}
+                  className="justify-start"
+                >
+                  {SOURCE_OPTIONS.map((opt) => (
+                    <ToggleGroupItem key={opt.value} value={opt.value} aria-label={opt.label}>
+                      {opt.label}
+                    </ToggleGroupItem>
+                  ))}
+                </ToggleGroup>
+              </div>
+            </div>
+          </div>
+
+          {hasActiveFilters && (
+            <div className="flex items-center justify-between text-sm text-muted-foreground">
+              <span>{filteredScans.length} von {scans.length} Scans</span>
+              <Button variant="ghost" size="sm" onClick={resetFilters} className="h-auto py-1">
+                <X className="w-4 h-4 mr-1" /> Filter zurücksetzen
+              </Button>
+            </div>
+          )}
+
+          {filteredScans.length === 0 ? (
+            <Card className="flex flex-col items-center justify-center p-12 text-center">
+              <Search className="w-12 h-12 text-muted-foreground mb-4 opacity-50" />
+              <h2 className="text-xl font-bold mb-2">Keine Treffer</h2>
+              <p className="text-muted-foreground mb-6 max-w-md">Für die aktuellen Filter- und Sucheinstellungen wurden keine Scans gefunden.</p>
+              <Button variant="outline" onClick={resetFilters}>
+                <X className="w-4 h-4 mr-1" /> Filter zurücksetzen
+              </Button>
+            </Card>
+          ) : (
+          <div className="space-y-4">
+          {filteredScans.map((scan) => (
             <Card key={scan.id} className="overflow-hidden hover:border-primary/50 transition-colors">
               <div className="flex flex-col sm:flex-row">
                 <Link href={`/berichte/${scan.id}`} className="flex-1 p-4 flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4">
@@ -131,7 +251,9 @@ export default function ScanHistory() {
               </div>
             </Card>
           ))}
-        </div>
+          </div>
+          )}
+        </>
       )}
     </div>
   );