feat(settings): implement Registrations tab

Replaces stub RegistrationsTab with a full read-only view grouped by client.
Handles all 4 states: loading skeleton, fetch error, host_path_unavailable,
empty list, and populated data with per-registration detail rows.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web-ui/src/app/settings/_components/registrations-tab.tsx

@@ -1 +1,134 @@
-export function RegistrationsTab() { return <div>Registrations tab — coming soon</div>; }
+"use client";
+
+import { Plug, AlertCircle } from "lucide-react";
+import { Card, CardContent } from "@/components/ui/card";
+import { Skeleton } from "@/components/ui/skeleton";
+import { Badge } from "@/components/ui/badge";
+import { useMcpRegistrations } from "@/lib/api/settings";
+
+export function RegistrationsTab() {
+  const { data, isPending, error } = useMcpRegistrations();
+
+  if (isPending) return <Skeleton className="h-64 w-full" />;
+  if (error) {
+    return (
+      <Card className="bg-surface border-danger/40">
+        <CardContent className="p-6 flex items-center gap-3 text-danger">
+          <AlertCircle className="w-5 h-5" />
+          <span>שגיאה: {error.message}</span>
+        </CardContent>
+      </Card>
+    );
+  }
+  if (!data) return null;
+
+  if (data.error === "host_path_unavailable") {
+    return (
+      <Card className="bg-surface border-warn/40">
+        <CardContent className="p-6">
+          <div className="flex items-center gap-3 text-warn mb-2">
+            <AlertCircle className="w-5 h-5" />
+            <span className="font-medium">תיקיית /host לא זמינה בקונטיינר</span>
+          </div>
+          <p className="text-sm text-ink-muted mb-2">
+            כדי להציג רישומי MCP, יש להוסיף volume mounts ב-Coolify.
+            ראה runbook ב-
+            <code dir="ltr" className="mx-1">
+              docs/runbooks/coolify-mcp-settings-volumes.md
+            </code>
+          </p>
+          {data.message && (
+            <p className="text-sm text-ink-muted">{data.message}</p>
+          )}
+        </CardContent>
+      </Card>
+    );
+  }
+
+  if (!data.registrations.length) {
+    return (
+      <Card className="bg-surface border-rule">
+        <CardContent className="p-6 text-ink-muted text-sm">
+          לא נמצאו רישומי MCP.
+        </CardContent>
+      </Card>
+    );
+  }
+
+  // Group by client
+  const groups = new Map<string, typeof data.registrations>();
+  for (const r of data.registrations) {
+    const arr = groups.get(r.client) ?? [];
+    arr.push(r);
+    groups.set(r.client, arr);
+  }
+
+  return (
+    <div className="space-y-4">
+      <div className="flex items-center gap-2 text-sm text-ink-muted">
+        <Plug className="w-4 h-4" />
+        סה&quot;כ {data.registrations.length} רישומים
+      </div>
+      {[...groups.entries()].map(([client, regs]) => (
+        <Card key={client} className="bg-surface border-rule">
+          <CardContent className="px-6 py-5">
+            <h2 className="text-navy text-lg mb-4 flex items-center gap-2">
+              {client}
+              <Badge variant="outline" className="text-[0.7rem]">
+                {regs.length}
+              </Badge>
+            </h2>
+            <div className="space-y-3">
+              {regs.map((r, i) => (
+                <div
+                  key={`${r.server_name}-${i}`}
+                  className="rounded-md border border-rule bg-rule-soft/20 p-4 space-y-2 text-sm"
+                >
+                  <div className="flex items-center gap-2 mb-1">
+                    <code dir="ltr" className="font-mono font-medium text-navy">
+                      {r.server_name}
+                    </code>
+                    <Badge variant="outline" className="text-[0.7rem]" dir="ltr">
+                      {r.transport}
+                    </Badge>
+                  </div>
+                  <div className="grid grid-cols-1 md:grid-cols-[100px_1fr] gap-x-3 gap-y-1.5 text-[0.82rem]">
+                    <span className="text-ink-muted">command:</span>
+                    <code dir="ltr" className="font-mono text-ink break-all">
+                      {r.command || "—"}
+                    </code>
+                    <span className="text-ink-muted">args:</span>
+                    <code dir="ltr" className="font-mono text-ink break-all">
+                      {r.args.length ? JSON.stringify(r.args) : "[]"}
+                    </code>
+                    <span className="text-ink-muted">cwd:</span>
+                    <code dir="ltr" className="font-mono text-ink break-all">
+                      {r.cwd || "—"}
+                    </code>
+                    <span className="text-ink-muted">env keys:</span>
+                    <div className="flex flex-wrap gap-1">
+                      {r.env_keys.length === 0 ? (
+                        <span className="text-ink-muted">—</span>
+                      ) : (
+                        r.env_keys.map((k) => (
+                          <Badge
+                            key={k}
+                            variant="outline"
+                            className="text-[0.7rem] font-mono"
+                            dir="ltr"
+                          >
+                            {k}
+                          </Badge>
+                        ))
+                      )}
+                    </div>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </CardContent>
+        </Card>
+      ))}
+    </div>
+  );
+}