Preview a checked file's content directly in the report

Task #41: Let users click a non-binary file in the "Geprüfte Dateien"
tree to view its stored text content, without re-downloading the archive.

Changes:
- lib/api-spec/openapi.yaml: added optional nullable `content` field to the
  ScanFile schema so the scan-detail response can carry stored file text.
- Regenerated API codegen (api-client-react + api-zod via orval) and ran
  the libs typecheck.
- artifacts/api-server/src/routes/scans.ts: serializeFile now returns
  `content` alongside the existing `hasContent`. Only used by the scan
  detail endpoint, so list responses are unaffected.
- artifacts/skillguard/src/pages/scan-report.tsx (FilesTree): non-binary
  file names are now clickable buttons that open a Dialog showing the
  stored content in a monospace, scrollable panel (ScrollArea). Binary
  files (hasContent === false) render as plain text and show a clear
  "Keine Vorschau verfügbar (Binärdatei)." message in the dialog guard.

Verification:
- tsc -b passes for both skillguard and api-server.
- relation + compare route tests pass (8 tests).
- Confirmed via API that the detail endpoint exposes content for a
  text-source scan (hasContent true) and null for binary .skill archives.

No new persistence: content is read from existing scan file data.

Replit-Task-Id: 931befbc-6ca3-4d15-b422-ac8e9f061f9f

artifacts/api-server/src/routes/scans.ts

@@ -68,6 +68,7 @@ function serializeFile(f: ScanFile) {
     size: f.size,
     hash: f.hash,
     hasContent: f.content !== null,
+    content: f.content,
   };
 }
 

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

@@ -17,6 +17,8 @@ import { Tabs, TabsList, TabsTrigger, TabsContent } from "@/components/ui/tabs";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import { Button } from "@/components/ui/button";
 import { Progress } from "@/components/ui/progress";
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription } from "@/components/ui/dialog";
+import { ScrollArea } from "@/components/ui/scroll-area";
 import { VerdictBadge, SeverityBadge, AxisBadge, CheckpointStatusBadge, CHECKPOINT_STATUS_LABELS, RelationBadge } from "@/components/ui-helpers";
 import { formatDate } from "@/lib/format";
 import { ShieldQuestion, ShieldAlert, AlertTriangle, Download, FileCode, CheckCircle2, Code, Shield, FileDown, ListChecks, Fingerprint, GitCompare, History, GitCommitVertical, Sparkles, Loader2, Folder, File as FileIcon, Copy, Check, ChevronRight, ChevronDown } from "lucide-react";
@@ -94,6 +96,7 @@ function FilesTree({ files }: { files: ScanReportFile[] }) {
   const [collapsed, setCollapsed] = useState<Set<string>>(() => new Set());
   const rows = useMemo(() => flattenFileTree(tree, collapsed), [tree, collapsed]);
   const [copiedHash, setCopiedHash] = useState<string | null>(null);
+  const [previewFile, setPreviewFile] = useState<ScanReportFile | null>(null);
 
   const toggleFolder = (path: string) => {
     setCollapsed((prev) => {
@@ -115,6 +118,7 @@ function FilesTree({ files }: { files: ScanReportFile[] }) {
   };
 
   return (
+    <>
     <div className="rounded-md border">
       <table className="w-full text-sm">
         <thead>
@@ -159,10 +163,16 @@ function FilesTree({ files }: { files: ScanReportFile[] }) {
               ) : (
                 <tr key={i} className="border-b last:border-0 hover:bg-muted/50 transition-colors">
                   <td className="p-4 font-mono">
-                    <span className="inline-flex items-center gap-2" style={{ paddingLeft: `${row.depth * 1.25 + 1}rem` }}>
+                    <button
+                      type="button"
+                      onClick={() => setPreviewFile(row.node.file)}
+                      title={row.node.file.hasContent ? "Inhalt anzeigen" : "Keine Vorschau verfügbar (Binärdatei)"}
+                      className="inline-flex items-center gap-2 text-left text-primary hover:underline"
+                      style={{ paddingLeft: `${row.depth * 1.25 + 1}rem` }}
+                    >
                       <FileIcon className="w-4 h-4 text-muted-foreground shrink-0" />
                       {row.node.name}
-                    </span>
+                    </button>
                   </td>
                   <td className="p-4">
                     <Badge variant="outline" className="capitalize">
@@ -197,6 +207,25 @@ function FilesTree({ files }: { files: ScanReportFile[] }) {
         </tbody>
       </table>
     </div>
+    <Dialog open={previewFile !== null} onOpenChange={(open) => !open && setPreviewFile(null)}>
+      <DialogContent className="max-w-3xl">
+        <DialogHeader>
+          <DialogTitle className="font-mono text-sm break-all">{previewFile?.path}</DialogTitle>
+          <DialogDescription>
+            {previewFile?.language ? `${previewFile.language} · ` : ""}
+            {previewFile?.size} B
+          </DialogDescription>
+        </DialogHeader>
+        {previewFile?.hasContent && previewFile.content != null ? (
+          <ScrollArea className="max-h-[60vh] rounded-md border bg-muted/30">
+            <pre className="p-4 text-xs font-mono whitespace-pre-wrap break-words">{previewFile.content}</pre>
+          </ScrollArea>
+        ) : (
+          <p className="text-sm text-muted-foreground">Keine Vorschau verfügbar (Binärdatei).</p>
+        )}
+      </DialogContent>
+    </Dialog>
+    </>
   );
 }
 

lib/api-client-react/src/generated/api.schemas.ts

@@ -218,6 +218,11 @@ export interface ScanFile {
   hash: string;
   /** Whether the text content was stored (false for binary files) */
   hasContent: boolean;
+  /**
+     * The stored text content of the file, or null for binary files
+     * @nullable
+     */
+  content?: string | null;
 }
 
 export type FindingAxis = typeof FindingAxis[keyof typeof FindingAxis];

lib/api-spec/openapi.yaml

@@ -607,6 +607,9 @@ components:
         hasContent:
           type: boolean
           description: Whether the text content was stored (false for binary files)
+        content:
+          type: ["string", "null"]
+          description: The stored text content of the file, or null for binary files
 
     Finding:
       type: object

lib/api-zod/src/generated/api.ts

@@ -232,7 +232,8 @@ export const GetScanResponse = zod.object({
   "language": zod.string().nullish(),
   "size": zod.number(),
   "hash": zod.string().describe('SHA-256 hash of the file content'),
-  "hasContent": zod.boolean().describe('Whether the text content was stored (false for binary files)')
+  "hasContent": zod.boolean().describe('Whether the text content was stored (false for binary files)'),
+  "content": zod.string().nullish().describe('The stored text content of the file, or null for binary files')
 })),
   "findings": zod.array(zod.object({
   "id": zod.number(),
@@ -317,7 +318,8 @@ export const GenerateScanDescriptionResponse = zod.object({
   "language": zod.string().nullish(),
   "size": zod.number(),
   "hash": zod.string().describe('SHA-256 hash of the file content'),
-  "hasContent": zod.boolean().describe('Whether the text content was stored (false for binary files)')
+  "hasContent": zod.boolean().describe('Whether the text content was stored (false for binary files)'),
+  "content": zod.string().nullish().describe('The stored text content of the file, or null for binary files')
 })),
   "findings": zod.array(zod.object({
   "id": zod.number(),

lib/api-zod/src/generated/types/scanFile.ts

@@ -17,4 +17,9 @@ export interface ScanFile {
   hash: string;
   /** Whether the text content was stored (false for binary files) */
   hasContent: boolean;
+  /**
+     * The stored text content of the file, or null for binary files
+     * @nullable
+     */
+  content?: string | null;
 }