test: guard against sf mcp server regression

README.md

@@ -578,7 +578,7 @@ SF ships with 24 extensions, all loaded automatically:
 | **Subagent**           | Delegated tasks with isolated context windows                                                                          |
 | **GitHub**             | Full-suite GitHub issues and PR management via `/gh` command                                                           |
 | **Mac Tools**          | macOS native app automation via Accessibility APIs                                                                     |
-| **MCP Client**         | Native MCP server integration via @modelcontextprotocol/sdk                                                            |
+| **MCP Client**         | Client-side connections to external MCP tool servers via @modelcontextprotocol/sdk; SF does not expose its workflow as MCP |
 | **Voice**              | Real-time speech-to-text transcription (macOS, Linux — Ubuntu 22.04+)                                                  |
 | **Slash Commands**     | Custom command creation                                                                                                |
 | **Ask User Questions** | Structured user input with single/multi-select                                                                         |

src/resources/extensions/sf/tests/no-sf-mcp-server.test.mjs

@@ -0,0 +1,22 @@
+import assert from "node:assert/strict";
+import { existsSync } from "node:fs";
+import { join } from "node:path";
+import { test } from "vitest";
+
+const repoRoot = join(import.meta.dirname, "../../../../..");
+
+test("sfMcpServer_when_removed_stays_absent", () => {
+	const forbiddenPaths = [
+		"packages/mcp-server",
+		"src/mcp-server.ts",
+		"src/resources/extensions/sf/mcp-server.js",
+	];
+
+	for (const relativePath of forbiddenPaths) {
+		assert.equal(
+			existsSync(join(repoRoot, relativePath)),
+			false,
+			`${relativePath} must not be recreated; SF is an MCP client only`,
+		);
+	}
+});