feat(ai-chat): inline Test button per external MCP server row (#170)

Add a per-row Test button to the external MCP servers list that shows the
connection result inline (no toasts). Extract the row into AiMcpServerRow so
each row owns its own useTestAiMcpServerMutation instance — independent loading
and result, no cross-row flicker.

States: idle (Test), pending (loading), success (green, "OK · N" with the tool
count), failure (red, "Failed"); a tooltip shows the tool list or the error.
The result resets when url/transport/headers change (the row is keyed by id, so
it does not remount). Backend, service and mutation are unchanged.

- ai-mcp-servers.tsx: AiMcpServerRow + Test button + reset effect + tooltip.
- i18n: add Failed / "OK · {{n}}" (en, ru) and ru Test / tool-list keys.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/client/public/locales/en-US/translation.json

@@ -715,6 +715,8 @@
   "Test": "Test",
   "Available tools": "Available tools",
   "No tools available": "No tools available",
+  "Failed": "Failed",
+  "OK · {{n}}": "OK · {{n}}",
   "Created successfully": "Created successfully",
   "Deleted successfully": "Deleted successfully",
   "Clear": "Clear",

apps/client/public/locales/ru-RU/translation.json

@@ -711,6 +711,11 @@
   "Edited by AI agent on behalf of {{name}}": "Отредактировано AI-агентом от имени {{name}}",
   "Failed to delete chat": "Не удалось удалить чат",
   "Failed to rename chat": "Не удалось переименовать чат",
+  "Failed": "Ошибка",
+  "OK · {{n}}": "OK · {{n}}",
+  "Test": "Тест",
+  "No tools available": "Инструменты недоступны",
+  "Available tools": "Доступные инструменты",
   "Minimize": "Свернуть",
   "No chats yet.": "Чатов пока нет.",
   "Send": "Отправить",

apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx

@@ -1,4 +1,4 @@
-import { useState } from "react";
+import { useEffect, useState } from "react";
 import {
   ActionIcon,
   Badge,
@@ -10,15 +10,24 @@ import {
   Stack,
   Switch,
   Text,
+  Tooltip,
 } from "@mantine/core";
 import { useDisclosure } from "@mantine/hooks";
 import { modals } from "@mantine/modals";
-import { IconPencil, IconPlus, IconTrash } from "@tabler/icons-react";
+import {
+  IconCheck,
+  IconPencil,
+  IconPlugConnected,
+  IconPlus,
+  IconTrash,
+  IconX,
+} from "@tabler/icons-react";
 import { useTranslation } from "react-i18next";
 import useUserRole from "@/hooks/use-user-role.tsx";
 import {
   useAiMcpServersQuery,
   useDeleteAiMcpServerMutation,
+  useTestAiMcpServerMutation,
   useUpdateAiMcpServerMutation,
 } from "@/features/workspace/queries/ai-mcp-server-query.ts";
 import { IAiMcpServer } from "@/features/workspace/services/ai-mcp-server-service.ts";
@@ -112,55 +121,15 @@ export default function AiMcpServers() {
 
       <Stack gap="xs" mt="sm">
         {servers?.map((server) => (
-          <Group key={server.id} justify="space-between" wrap="nowrap">
-            <Stack gap={2} style={{ minWidth: 0 }}>
-              <Group gap="xs">
-                <Text fw={500} truncate>
-                  {server.name}
-                </Text>
-                <Badge size="xs" variant="light">
-                  {server.transport.toUpperCase()}
-                </Badge>
-              </Group>
-              <Text
-                size="xs"
-                c="dimmed"
-                truncate
-                style={{ fontFamily: "ui-monospace, Menlo, monospace" }}
-              >
-                {server.url}
-              </Text>
-            </Stack>
-
-            <Group gap="xs" wrap="nowrap">
-              <Switch
-                size="sm"
-                checked={server.enabled}
-                aria-label={t("Enabled")}
-                onChange={(event) =>
-                  updateMutation.mutate({
-                    id: server.id,
-                    enabled: event.currentTarget.checked,
-                  })
-                }
-              />
-              <ActionIcon
-                variant="subtle"
-                aria-label={t("Edit")}
-                onClick={() => openEdit(server)}
-              >
-                <IconPencil size={16} />
-              </ActionIcon>
-              <ActionIcon
-                variant="subtle"
-                color="red"
-                aria-label={t("Delete")}
-                onClick={() => confirmDelete(server)}
-              >
-                <IconTrash size={16} />
-              </ActionIcon>
-            </Group>
-          </Group>
+          <AiMcpServerRow
+            key={server.id}
+            server={server}
+            onEdit={openEdit}
+            onDelete={confirmDelete}
+            onToggleEnabled={(enabled) =>
+              updateMutation.mutate({ id: server.id, enabled })
+            }
+          />
         ))}
       </Stack>
 
@@ -180,3 +149,132 @@ export default function AiMcpServers() {
     </Paper>
   );
 }
+
+interface AiMcpServerRowProps {
+  server: IAiMcpServer;
+  onEdit: (server: IAiMcpServer) => void;
+  onDelete: (server: IAiMcpServer) => void;
+  onToggleEnabled: (enabled: boolean) => void;
+}
+
+/**
+ * A single external MCP server row: name/badge/url on the left and the
+ * Test / Switch / Edit / Delete controls on the right. Each row owns its own
+ * `useTestAiMcpServerMutation()` so the inline Test result and loading state are
+ * independent per row (a shared mutation would make `isPending` global and make
+ * every row flicker).
+ */
+function AiMcpServerRow({
+  server,
+  onEdit,
+  onDelete,
+  onToggleEnabled,
+}: AiMcpServerRowProps) {
+  const { t } = useTranslation();
+  const testMutation = useTestAiMcpServerMutation();
+  const result = testMutation.data;
+
+  // The row is keyed by `server.id`, so editing the connection-relevant fields
+  // (url/transport/headers) does NOT remount it — an old success/failure result
+  // would otherwise stick. Clear the result when those fields change.
+  useEffect(() => {
+    testMutation.reset();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [server.url, server.transport, server.hasHeaders]);
+
+  // Tooltip text describes the cause/details; disabled while there is no result.
+  let tooltipLabel = "";
+  if (result?.ok) {
+    tooltipLabel =
+      result.tools.length > 0
+        ? result.tools.join(", ")
+        : t("No tools available");
+  } else if (result && result.ok === false) {
+    tooltipLabel = result.error;
+  }
+
+  // Pick the button presentation from the current test state. Color is never the
+  // only signal — the label changes too (a11y / colorblind-friendly).
+  let buttonColor: string | undefined;
+  let buttonVariant = "default";
+  let buttonIcon = <IconPlugConnected size={16} />;
+  let buttonLabel = t("Test");
+  if (result?.ok) {
+    buttonColor = "green";
+    buttonVariant = "light";
+    buttonIcon = <IconCheck size={16} />;
+    buttonLabel = t("OK · {{n}}", { n: result.tools.length });
+  } else if (result && result.ok === false) {
+    buttonColor = "red";
+    buttonVariant = "light";
+    buttonIcon = <IconX size={16} />;
+    buttonLabel = t("Failed");
+  }
+
+  return (
+    <Group justify="space-between" wrap="nowrap">
+      <Stack gap={2} style={{ minWidth: 0 }}>
+        <Group gap="xs">
+          <Text fw={500} truncate>
+            {server.name}
+          </Text>
+          <Badge size="xs" variant="light">
+            {server.transport.toUpperCase()}
+          </Badge>
+        </Group>
+        <Text
+          size="xs"
+          c="dimmed"
+          truncate
+          style={{ fontFamily: "ui-monospace, Menlo, monospace" }}
+        >
+          {server.url}
+        </Text>
+      </Stack>
+
+      <Group gap="xs" wrap="nowrap">
+        {/* Always clickable: testing a disabled server before enabling it is useful. */}
+        <Tooltip
+          label={tooltipLabel}
+          disabled={!result}
+          multiline
+          maw={320}
+          withinPortal
+        >
+          <Button
+            size="xs"
+            miw={88}
+            color={buttonColor}
+            variant={buttonVariant}
+            leftSection={testMutation.isPending ? undefined : buttonIcon}
+            loading={testMutation.isPending}
+            onClick={() => testMutation.mutate(server.id)}
+          >
+            {buttonLabel}
+          </Button>
+        </Tooltip>
+        <Switch
+          size="sm"
+          checked={server.enabled}
+          aria-label={t("Enabled")}
+          onChange={(event) => onToggleEnabled(event.currentTarget.checked)}
+        />
+        <ActionIcon
+          variant="subtle"
+          aria-label={t("Edit")}
+          onClick={() => onEdit(server)}
+        >
+          <IconPencil size={16} />
+        </ActionIcon>
+        <ActionIcon
+          variant="subtle"
+          color="red"
+          aria-label={t("Delete")}
+          onClick={() => onDelete(server)}
+        >
+          <IconTrash size={16} />
+        </ActionIcon>
+      </Group>
+    </Group>
+  );
+}