feat: add unified Settings sheet, MCP indicator, and Docker host config

- Add AppSettingsSheet (gear icon in Toolbar) with MCP, Docker, and AI sections
- MCP Server: toggle on/off, port config, status badge, endpoint URL with copy
- Docker: local/remote daemon selector with remote URL input
- AI: moved Ollama settings into the unified sheet
- MCP status probes actual TCP port for reliable running detection
- Docker commands respect configurable docker host (-H flag) for remote daemons
- MCP server supports graceful shutdown via tokio watch channel
- Settings persisted to app_settings.json alongside existing config files
- StatusBar shows MCP indicator (green/gray dot) with tooltip

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

src/components/layout/StatusBar.tsx

@@ -1,7 +1,9 @@
 import { useAppStore } from "@/stores/app-store";
 import { useConnections } from "@/hooks/use-connections";
+import { useMcpStatus } from "@/hooks/use-settings";
 import { Circle } from "lucide-react";
 import { EnvironmentBadge } from "@/components/connections/EnvironmentBadge";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
 
 function formatDbVersion(version: string): string {
   const gpMatch = version.match(/Greenplum Database ([\d.]+)/i);
@@ -21,6 +23,7 @@ interface Props {
 export function StatusBar({ rowCount, executionTime }: Props) {
   const { activeConnectionId, connectedIds, readOnlyMap, pgVersion } = useAppStore();
   const { data: connections } = useConnections();
+  const { data: mcpStatus } = useMcpStatus();
 
   const activeConn = connections?.find((c) => c.id === activeConnectionId);
   const isConnected = activeConnectionId
@@ -62,6 +65,25 @@ export function StatusBar({ rowCount, executionTime }: Props) {
       <div className="flex items-center gap-3">
         {rowCount != null && <span>{rowCount.toLocaleString()} rows</span>}
         {executionTime != null && <span>{executionTime} ms</span>}
+        <Tooltip>
+          <TooltipTrigger asChild>
+            <span className="flex items-center gap-1 cursor-default">
+              <span
+                className={`inline-block h-1.5 w-1.5 rounded-full ${
+                  mcpStatus?.running
+                    ? "bg-green-500"
+                    : "bg-muted-foreground/30"
+                }`}
+              />
+              <span>MCP</span>
+            </span>
+          </TooltipTrigger>
+          <TooltipContent side="top">
+            <p className="text-xs">
+              MCP Server {mcpStatus?.running ? `running on :${mcpStatus.port}` : "stopped"}
+            </p>
+          </TooltipContent>
+        </Tooltip>
       </div>
     </div>
   );

src/components/layout/Toolbar.tsx

@@ -8,13 +8,15 @@ import { ReadOnlyToggle } from "@/components/layout/ReadOnlyToggle";
 import { useAppStore } from "@/stores/app-store";
 import { useConnections, useReconnect } from "@/hooks/use-connections";
 import { toast } from "sonner";
-import { Database, Plus, RefreshCw, Search } from "lucide-react";
+import { Database, Plus, RefreshCw, Search, Settings } from "lucide-react";
 import type { ConnectionConfig, Tab } from "@/types";
 import { getEnvironment } from "@/lib/environment";
+import { AppSettingsSheet } from "@/components/settings/AppSettingsSheet";
 
 export function Toolbar() {
   const [listOpen, setListOpen] = useState(false);
   const [dialogOpen, setDialogOpen] = useState(false);
+  const [settingsOpen, setSettingsOpen] = useState(false);
   const [editingConn, setEditingConn] = useState<ConnectionConfig | null>(null);
   const { activeConnectionId, currentDatabase, addTab } = useAppStore();
   const { data: connections } = useConnections();
@@ -116,6 +118,16 @@ export function Toolbar() {
         </Button>
 
         <div className="flex-1" />
+
+        <Button
+          variant="ghost"
+          size="sm"
+          className="h-7 w-7 p-0"
+          onClick={() => setSettingsOpen(true)}
+          title="Settings"
+        >
+          <Settings className="h-3.5 w-3.5" />
+        </Button>
       </div>
 
       <ConnectionList
@@ -136,6 +148,11 @@ export function Toolbar() {
         onOpenChange={setDialogOpen}
         connection={editingConn}
       />
+
+      <AppSettingsSheet
+        open={settingsOpen}
+        onOpenChange={setSettingsOpen}
+      />
     </>
   );
 }

src/components/settings/AppSettingsSheet.tsx

@@ -0,0 +1,299 @@
+import { useState, useEffect } from "react";
+import {
+  Sheet,
+  SheetContent,
+  SheetHeader,
+  SheetTitle,
+  SheetDescription,
+  SheetFooter,
+} from "@/components/ui/sheet";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import { Separator } from "@/components/ui/separator";
+import { useAppSettings, useSaveAppSettings, useMcpStatus } from "@/hooks/use-settings";
+import { useAiSettings, useSaveAiSettings, useOllamaModels } from "@/hooks/use-ai";
+import { RefreshCw, Loader2, Copy, Check } from "lucide-react";
+import { toast } from "sonner";
+import type { AppSettings, DockerHost } from "@/types";
+
+interface Props {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+}
+
+export function AppSettingsSheet({ open, onOpenChange }: Props) {
+  const { data: appSettings } = useAppSettings();
+  const { data: mcpStatus } = useMcpStatus();
+  const saveAppMutation = useSaveAppSettings();
+
+  const { data: aiSettings } = useAiSettings();
+  const saveAiMutation = useSaveAiSettings();
+
+  // MCP state
+  const [mcpEnabled, setMcpEnabled] = useState(true);
+  const [mcpPort, setMcpPort] = useState(9427);
+
+  // Docker state
+  const [dockerHost, setDockerHost] = useState<DockerHost>("local");
+  const [dockerRemoteUrl, setDockerRemoteUrl] = useState("");
+
+  // AI state
+  const [ollamaUrl, setOllamaUrl] = useState("http://localhost:11434");
+  const [aiModel, setAiModel] = useState("");
+
+  const [copied, setCopied] = useState(false);
+
+  // Sync form with loaded settings
+  useEffect(() => {
+    if (appSettings) {
+      setMcpEnabled(appSettings.mcp.enabled);
+      setMcpPort(appSettings.mcp.port);
+      setDockerHost(appSettings.docker.host);
+      setDockerRemoteUrl(appSettings.docker.remote_url ?? "");
+    }
+  }, [appSettings]);
+
+  useEffect(() => {
+    if (aiSettings) {
+      setOllamaUrl(aiSettings.ollama_url);
+      setAiModel(aiSettings.model);
+    }
+  }, [aiSettings]);
+
+  const {
+    data: models,
+    isLoading: modelsLoading,
+    isError: modelsError,
+    refetch: refetchModels,
+  } = useOllamaModels(ollamaUrl);
+
+  const mcpEndpoint = `http://127.0.0.1:${mcpPort}/mcp`;
+
+  const handleCopy = async () => {
+    await navigator.clipboard.writeText(mcpEndpoint);
+    setCopied(true);
+    setTimeout(() => setCopied(false), 2000);
+  };
+
+  const handleSave = () => {
+    const settings: AppSettings = {
+      mcp: { enabled: mcpEnabled, port: mcpPort },
+      docker: {
+        host: dockerHost,
+        remote_url: dockerHost === "remote" ? dockerRemoteUrl || undefined : undefined,
+      },
+    };
+
+    saveAppMutation.mutate(settings, {
+      onSuccess: () => {
+        toast.success("Settings saved");
+      },
+      onError: (err) =>
+        toast.error("Failed to save settings", { description: String(err) }),
+    });
+
+    // Save AI settings separately
+    saveAiMutation.mutate(
+      { provider: "ollama", ollama_url: ollamaUrl, model: aiModel },
+      {
+        onError: (err) =>
+          toast.error("Failed to save AI settings", { description: String(err) }),
+      }
+    );
+  };
+
+  return (
+    <Sheet open={open} onOpenChange={onOpenChange}>
+      <SheetContent side="right" className="w-[400px] sm:max-w-[400px] overflow-y-auto">
+        <SheetHeader>
+          <SheetTitle>Settings</SheetTitle>
+          <SheetDescription>Application configuration</SheetDescription>
+        </SheetHeader>
+
+        <div className="flex flex-col gap-6 px-4">
+          {/* MCP Server */}
+          <section className="flex flex-col gap-3">
+            <h3 className="text-sm font-medium">MCP Server</h3>
+
+            <div className="flex items-center justify-between">
+              <span className="text-xs text-muted-foreground">Enabled</span>
+              <Button
+                size="sm"
+                variant={mcpEnabled ? "default" : "outline"}
+                className="h-6 text-xs px-3"
+                onClick={() => setMcpEnabled(!mcpEnabled)}
+              >
+                {mcpEnabled ? "On" : "Off"}
+              </Button>
+            </div>
+
+            <div className="flex flex-col gap-1.5">
+              <label className="text-xs text-muted-foreground">Port</label>
+              <Input
+                type="number"
+                value={mcpPort}
+                onChange={(e) => setMcpPort(Number(e.target.value))}
+                className="h-8 text-xs"
+                min={1}
+                max={65535}
+              />
+            </div>
+
+            <div className="flex items-center gap-2">
+              <span className="text-xs text-muted-foreground">Status:</span>
+              <span className="flex items-center gap-1.5 text-xs">
+                <span
+                  className={`inline-block h-2 w-2 rounded-full ${
+                    mcpStatus?.running
+                      ? "bg-green-500"
+                      : "bg-muted-foreground/30"
+                  }`}
+                />
+                {mcpStatus?.running ? "Running" : "Stopped"}
+              </span>
+            </div>
+
+            <div className="flex flex-col gap-1.5">
+              <label className="text-xs text-muted-foreground">Endpoint</label>
+              <div className="flex items-center gap-1">
+                <code className="flex-1 rounded bg-muted px-2 py-1 text-xs font-mono truncate">
+                  {mcpEndpoint}
+                </code>
+                <Button
+                  size="sm"
+                  variant="ghost"
+                  className="h-7 w-7 p-0"
+                  onClick={handleCopy}
+                  title="Copy endpoint URL"
+                >
+                  {copied ? (
+                    <Check className="h-3 w-3 text-green-500" />
+                  ) : (
+                    <Copy className="h-3 w-3" />
+                  )}
+                </Button>
+              </div>
+            </div>
+          </section>
+
+          <Separator />
+
+          {/* Docker */}
+          <section className="flex flex-col gap-3">
+            <h3 className="text-sm font-medium">Docker</h3>
+
+            <div className="flex flex-col gap-1.5">
+              <label className="text-xs text-muted-foreground">Docker Host</label>
+              <Select value={dockerHost} onValueChange={(v) => setDockerHost(v as DockerHost)}>
+                <SelectTrigger className="h-8 text-xs">
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="local">Local</SelectItem>
+                  <SelectItem value="remote">Remote</SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
+
+            {dockerHost === "remote" && (
+              <div className="flex flex-col gap-1.5">
+                <label className="text-xs text-muted-foreground">Remote URL</label>
+                <Input
+                  value={dockerRemoteUrl}
+                  onChange={(e) => setDockerRemoteUrl(e.target.value)}
+                  placeholder="tcp://192.168.1.100:2375"
+                  className="h-8 text-xs"
+                />
+              </div>
+            )}
+          </section>
+
+          <Separator />
+
+          {/* AI */}
+          <section className="flex flex-col gap-3">
+            <h3 className="text-sm font-medium">AI</h3>
+
+            <div className="flex flex-col gap-1.5">
+              <label className="text-xs text-muted-foreground">Provider</label>
+              <Select value="ollama" disabled>
+                <SelectTrigger className="h-8 text-xs">
+                  <SelectValue />
+                </SelectTrigger>
+                <SelectContent>
+                  <SelectItem value="ollama">Ollama</SelectItem>
+                </SelectContent>
+              </Select>
+            </div>
+
+            <div className="flex flex-col gap-1.5">
+              <label className="text-xs text-muted-foreground">Ollama URL</label>
+              <Input
+                value={ollamaUrl}
+                onChange={(e) => setOllamaUrl(e.target.value)}
+                placeholder="http://localhost:11434"
+                className="h-8 text-xs"
+              />
+            </div>
+
+            <div className="flex flex-col gap-1.5">
+              <div className="flex items-center justify-between">
+                <label className="text-xs text-muted-foreground">Model</label>
+                <Button
+                  size="sm"
+                  variant="ghost"
+                  className="h-5 w-5 p-0"
+                  onClick={() => refetchModels()}
+                  disabled={modelsLoading}
+                  title="Refresh models"
+                >
+                  {modelsLoading ? (
+                    <Loader2 className="h-3 w-3 animate-spin" />
+                  ) : (
+                    <RefreshCw className="h-3 w-3" />
+                  )}
+                </Button>
+              </div>
+              {modelsError ? (
+                <p className="text-xs text-destructive">Cannot connect to Ollama</p>
+              ) : (
+                <Select value={aiModel} onValueChange={setAiModel}>
+                  <SelectTrigger className="h-8 w-full text-xs">
+                    <SelectValue placeholder="Select a model" />
+                  </SelectTrigger>
+                  <SelectContent>
+                    {models?.map((m) => (
+                      <SelectItem key={m.name} value={m.name}>
+                        {m.name}
+                      </SelectItem>
+                    ))}
+                  </SelectContent>
+                </Select>
+              )}
+            </div>
+          </section>
+        </div>
+
+        <SheetFooter>
+          <Button
+            className="w-full"
+            onClick={handleSave}
+            disabled={saveAppMutation.isPending}
+          >
+            {saveAppMutation.isPending ? (
+              <Loader2 className="h-4 w-4 animate-spin mr-2" />
+            ) : null}
+            Save
+          </Button>
+        </SheetFooter>
+      </SheetContent>
+    </Sheet>
+  );
+}

src/hooks/use-settings.ts

@@ -0,0 +1,30 @@
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { getAppSettings, saveAppSettings, getMcpStatus } from "@/lib/tauri";
+import type { AppSettings } from "@/types";
+
+export function useAppSettings() {
+  return useQuery({
+    queryKey: ["app-settings"],
+    queryFn: getAppSettings,
+    staleTime: Infinity,
+  });
+}
+
+export function useSaveAppSettings() {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: (settings: AppSettings) => saveAppSettings(settings),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["app-settings"] });
+      queryClient.invalidateQueries({ queryKey: ["mcp-status"] });
+    },
+  });
+}
+
+export function useMcpStatus() {
+  return useQuery({
+    queryKey: ["mcp-status"],
+    queryFn: getMcpStatus,
+    refetchInterval: 5000,
+  });
+}

src/lib/tauri.ts

@@ -33,6 +33,8 @@ import type {
   CloneProgress,
   CloneResult,
   TuskContainer,
+  AppSettings,
+  McpStatus,
 } from "@/types";
 
 // Connections
@@ -320,3 +322,13 @@ export const onCloneProgress = (
   callback: (p: CloneProgress) => void
 ): Promise<UnlistenFn> =>
   listen<CloneProgress>("clone-progress", (e) => callback(e.payload));
+
+// App Settings
+export const getAppSettings = () =>
+  invoke<AppSettings>("get_app_settings");
+
+export const saveAppSettings = (settings: AppSettings) =>
+  invoke<void>("save_app_settings", { settings });
+
+export const getMcpStatus = () =>
+  invoke<McpStatus>("get_mcp_status");

src/types/index.ts

@@ -323,6 +323,30 @@ export interface ErdData {
   relationships: ErdRelationship[];
 }
 
+// App Settings
+export type DockerHost = "local" | "remote";
+
+export interface McpSettings {
+  enabled: boolean;
+  port: number;
+}
+
+export interface DockerSettings {
+  host: DockerHost;
+  remote_url?: string;
+}
+
+export interface AppSettings {
+  mcp: McpSettings;
+  docker: DockerSettings;
+}
+
+export interface McpStatus {
+  enabled: boolean;
+  port: number;
+  running: boolean;
+}
+
 // Docker
 export interface DockerStatus {
   installed: boolean;