feat: show live build version in web UI

- /api/version returns version, commitSha, buildDate, trashRetentionDays
- CI passes COMMIT_SHA (full), BUILD_DATE and VERSION (git tag) as
  docker build args; Dockerfile bakes them as env
- sidebar footer shows version/sha linked to the Gitea commit
- admin System tab shows version, commit link, build date, trash retention

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

@@ -8,4 +8,14 @@ router.get("/healthz", (_req, res) => {
   res.json(data);
 });
 
+router.get("/version", (_req, res) => {
+  const retention = Number(process.env["TRASH_RETENTION_DAYS"] ?? "0");
+  res.json({
+    version: process.env["VERSION"] || "dev",
+    commitSha: process.env["COMMIT_SHA"] || null,
+    buildDate: process.env["BUILD_DATE"] || null,
+    trashRetentionDays: Number.isFinite(retention) ? retention : 0,
+  });
+});
+
 export default router;

artifacts/toolrate/src/components/layout.tsx

@@ -1,6 +1,7 @@
 import { Link, useLocation } from "wouter";
 import { LayoutDashboard, Wrench, PlusCircle, BarChart3, LogIn, LogOut, User, ShieldCheck, AlertTriangle, Trash2 } from "lucide-react";
 import { useAuth } from "@/hooks/use-auth";
+import { useGetVersion, getGetVersionQueryKey } from "@workspace/api-client-react";
 import { Button } from "@/components/ui/button";
 import { Skeleton } from "@/components/ui/skeleton";
 import { ThemeToggle } from "@/components/theme-toggle";
@@ -8,6 +9,9 @@ import { ThemeToggle } from "@/components/theme-toggle";
 export function Layout({ children }: { children: React.ReactNode }) {
   const [location] = useLocation();
   const { user, isLoading, isAuthenticated, isAdmin, isLocalMode, tier, hasFeature, login, logout } = useAuth();
+  const { data: version } = useGetVersion({
+    query: { queryKey: getGetVersionQueryKey(), staleTime: Infinity, retry: false },
+  });
 
   const links = [
     { href: "/", label: "Dashboard", icon: LayoutDashboard },
@@ -95,6 +99,24 @@ export function Layout({ children }: { children: React.ReactNode }) {
             </Button>
           )}
         </div>
+        <div className="px-4 py-2.5 border-t flex items-center justify-between text-[11px] text-muted-foreground">
+          <span className="font-medium">toolr</span>
+          {version?.commitSha ? (
+            <a
+              href={`https://git.kubebase.de/admin/tool-evaluator/commit/${version.commitSha}`}
+              target="_blank"
+              rel="noreferrer"
+              className="font-mono hover:underline"
+              title={version.commitSha}
+            >
+              {version.version && version.version !== "dev"
+                ? version.version
+                : `sha-${version.commitSha.slice(0, 7)}`}
+            </a>
+          ) : version?.version && version.version !== "dev" ? (
+            <span className="font-mono">{version.version}</span>
+          ) : null}
+        </div>
       </aside>
 
       <main className="flex-1 flex flex-col min-w-0">

artifacts/toolrate/src/pages/admin.tsx

@@ -6,8 +6,10 @@ import {
   useUpdateUser,
   useDeleteUser,
   useListAuditLogs,
+  useGetVersion,
   getListUsersQueryKey,
   getListAuditLogsQueryKey,
+  getGetVersionQueryKey,
 } from "@workspace/api-client-react";
 import { useQueryClient } from "@tanstack/react-query";
 import { useAuth } from "@/hooks/use-auth";
@@ -22,7 +24,7 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Skeleton } from "@/components/ui/skeleton";
 import { useToast } from "@/hooks/use-toast";
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
-import { Users, ScrollText, ShieldAlert, Plus, Pencil, Trash2, Clock, AlertTriangle, Wrench } from "lucide-react";
+import { Users, ScrollText, ShieldAlert, Plus, Pencil, Trash2, Clock, AlertTriangle, Wrench, Server } from "lucide-react";
 import { format } from "date-fns";
 import { AdminToolsTab } from "@/components/admin-tools-tab";
 
@@ -49,6 +51,9 @@ export default function Admin() {
     { limit: 100 },
     { query: { queryKey: getListAuditLogsQueryKey({ limit: 100 }), enabled: isAdmin } },
   );
+  const { data: versionInfo } = useGetVersion({
+    query: { queryKey: getGetVersionQueryKey(), staleTime: Infinity, retry: false, enabled: isAdmin },
+  });
 
   const createUser = useCreateUser();
   const updateUser = useUpdateUser();
@@ -154,6 +159,9 @@ export default function Admin() {
             <TabsTrigger value="audit" className="gap-2">
               <ScrollText className="w-4 h-4" /> Audit Log
             </TabsTrigger>
+            <TabsTrigger value="system" className="gap-2">
+              <Server className="w-4 h-4" /> System
+            </TabsTrigger>
           </TabsList>
 
           <TabsContent value="users">
@@ -274,6 +282,53 @@ export default function Admin() {
               </CardContent>
             </Card>
           </TabsContent>
+
+          <TabsContent value="system">
+            <Card>
+              <CardHeader>
+                <CardTitle>System</CardTitle>
+                <CardDescription>Build information of the currently live deployment.</CardDescription>
+              </CardHeader>
+              <CardContent>
+                <div className="divide-y">
+                  <div className="flex items-center justify-between py-3">
+                    <span className="text-sm text-muted-foreground">Version</span>
+                    <span className="text-sm font-medium">{versionInfo?.version || "dev"}</span>
+                  </div>
+                  <div className="flex items-center justify-between py-3">
+                    <span className="text-sm text-muted-foreground">Commit</span>
+                    {versionInfo?.commitSha ? (
+                      <a
+                        href={`https://git.kubebase.de/admin/tool-evaluator/commit/${versionInfo.commitSha}`}
+                        target="_blank"
+                        rel="noreferrer"
+                        className="text-sm font-mono text-primary hover:underline"
+                        title={versionInfo.commitSha}
+                      >
+                        {versionInfo.commitSha.slice(0, 7)}
+                      </a>
+                    ) : (
+                      <span className="text-sm text-muted-foreground">—</span>
+                    )}
+                  </div>
+                  <div className="flex items-center justify-between py-3">
+                    <span className="text-sm text-muted-foreground">Build date</span>
+                    <span className="text-sm">
+                      {versionInfo?.buildDate ? format(new Date(versionInfo.buildDate), "dd.MM.yyyy HH:mm") : "—"}
+                    </span>
+                  </div>
+                  <div className="flex items-center justify-between py-3">
+                    <span className="text-sm text-muted-foreground">Trash retention</span>
+                    <span className="text-sm">
+                      {(versionInfo?.trashRetentionDays ?? 0) > 0
+                        ? `${versionInfo?.trashRetentionDays} days`
+                        : "Keep forever"}
+                    </span>
+                  </div>
+                </div>
+              </CardContent>
+            </Card>
+          </TabsContent>
         </Tabs>
       </div>