feat(client): remove Tavily preset button from MCP server form

Drop the "Use Tavily preset" quick-fill button from the Add server form
and its now-dead supporting code:
- remove the preset JSX block, applyTavilyPreset handler and TAVILY_PRESET
  constant in ai-mcp-server-form.tsx
- drop the now-unused McpTransport import
- remove the unused "Use Tavily preset" i18n key from en-US translations

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

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

@@ -708,7 +708,6 @@
   "Authorization header": "Authorization header",
   "Tool allowlist": "Tool allowlist",
   "Optional. Leave empty to allow all tools the server exposes.": "Optional. Leave empty to allow all tools the server exposes.",
-  "Use Tavily preset": "Use Tavily preset",
   "Test": "Test",
   "Available tools": "Available tools",
   "No tools available": "No tools available",

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

@@ -26,7 +26,6 @@ import {
   IAiMcpServer,
   IAiMcpServerCreate,
   IAiMcpServerUpdate,
-  McpTransport,
 } from "@/features/workspace/services/ai-mcp-server-service.ts";
 
 const formSchema = z.object({
@@ -62,13 +61,6 @@ function buildInitialValues(server?: IAiMcpServer): FormValues {
   };
 }
 
-// Tavily preset (§8.10): the API key goes in the Authorization HEADER, not the URL.
-const TAVILY_PRESET = {
-  name: "Tavily",
-  transport: "http" as McpTransport,
-  url: "https://mcp.tavily.com/mcp/",
-};
-
 export default function AiMcpServerForm({
   server,
   onClose,
@@ -155,28 +147,11 @@ export default function AiMcpServerForm({
     form.setFieldValue("authHeader", "");
   }
 
-  function applyTavilyPreset() {
-    form.setFieldValue("name", TAVILY_PRESET.name);
-    form.setFieldValue("transport", TAVILY_PRESET.transport);
-    form.setFieldValue("url", TAVILY_PRESET.url);
-    // Prefill the Bearer prefix; the admin pastes their Tavily key after it.
-    form.setFieldValue("authHeader", "Bearer ");
-    setHeadersCleared(false);
-  }
-
   const testResult = testMutation.data;
   const isSaving = createMutation.isPending || updateMutation.isPending;
 
   return (
     <Stack>
-      {!isEdit && (
-        <Group justify="flex-start">
-          <Button variant="default" size="compact-sm" onClick={applyTavilyPreset}>
-            {t("Use Tavily preset")}
-          </Button>
-        </Group>
-      )}
-
       <TextInput
         label={t("Server name")}
         {...form.getInputProps("name")}