feat: ship docker as a first-party in-process plugin

Moves docker backend and frontend into plugins/docker/, alongside
ssh-terminal. Adds a host editor tab seam, a dashboard card registry,
and a build step to compile plugin backends into dist.

plugins/docker/frontend/components/ContainerList.tsx

@@ -0,0 +1,83 @@
+import React from "react";
+import { Box } from "lucide-react";
+import { useTranslation } from "react-i18next";
+import type { DockerContainer } from "@/types";
+import { ContainerCard } from "./ContainerCard.tsx";
+
+interface ContainerListProps {
+  containers: DockerContainer[];
+  sessionId: string;
+  onSelectContainer: (containerId: string) => void;
+  selectedContainerId?: string | null;
+  onRefresh?: () => void;
+  search?: string;
+  statusFilter?: string;
+}
+
+export function ContainerList({
+  containers,
+  sessionId,
+  onSelectContainer,
+  selectedContainerId = null,
+  onRefresh,
+  search = "",
+  statusFilter = "all",
+}: ContainerListProps): React.ReactElement {
+  const { t } = useTranslation();
+
+  const filtered = React.useMemo(() => {
+    return containers.filter((c) => {
+      const name = c.name.startsWith("/") ? c.name.slice(1) : c.name;
+      const matchesSearch =
+        name.toLowerCase().includes(search.toLowerCase()) ||
+        c.image.toLowerCase().includes(search.toLowerCase()) ||
+        c.id.toLowerCase().includes(search.toLowerCase());
+      return (
+        matchesSearch && (statusFilter === "all" || c.state === statusFilter)
+      );
+    });
+  }, [containers, search, statusFilter]);
+
+  if (containers.length === 0) {
+    return (
+      <div className="flex flex-col items-center justify-center h-full opacity-20 py-20">
+        <Box className="size-16 mb-4" />
+        <span className="text-xl font-bold uppercase tracking-widest">
+          {t("docker.noContainersFound")}
+        </span>
+        <span className="text-xs font-semibold">
+          {t("docker.noContainersFoundHint")}
+        </span>
+      </div>
+    );
+  }
+
+  if (filtered.length === 0) {
+    return (
+      <div className="flex flex-col items-center justify-center h-full opacity-20 py-20">
+        <Box className="size-16 mb-4" />
+        <span className="text-xl font-bold uppercase tracking-widest">
+          {t("docker.noContainersMatchFilters")}
+        </span>
+        <span className="text-xs font-semibold">
+          {t("docker.noContainersMatchFiltersHint")}
+        </span>
+      </div>
+    );
+  }
+
+  return (
+    <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3">
+      {filtered.map((container) => (
+        <ContainerCard
+          key={container.id}
+          container={container}
+          sessionId={sessionId}
+          onSelect={() => onSelectContainer(container.id)}
+          isSelected={selectedContainerId === container.id}
+          onRefresh={onRefresh}
+        />
+      ))}
+    </div>
+  );
+}