fix(server-tests): unblock Windows CI for Claude SDK + .exe launch test

- spawn.launch-regression: insert `--` between `node -e <body>` and the
  user JSON args. Without it Node treats `--config` as a CLI option and
  exits with code 9 ("bad option"). The `--` stops Node's flag parsing
  so userArgs land in process.argv intact.
- claude-agent.integration + claude-sdk-behavior: inject
  spawnClaudeCodeProcess that routes the SDK's launch through our
  spawnProcess (shell: false). On Windows the SDK's default spawn fails
  with EINVAL when pathToClaudeCodeExecutable resolves to a `.cmd` shim
  (CVE-2024-27980). This mirrors what claude-agent.ts does in production.
- 3 cleanup sites (event-stream, integration, sdk-behavior): swallow
  EBUSY/ENOTEMPTY/EPERM around rmSync. The maxRetries window doesn't
  reliably win the Windows cwd-lock race after Claude exits; the OS will
  reap the tmpdir.

packages/server/src/server/agent/providers/__tests__/claude-agent.event-stream.integration.test.ts

@@ -74,7 +74,14 @@ async function createSession(params?: {
 
 async function cleanupSession(handle: { cwd: string; session: AgentSession }): Promise<void> {
   await handle.session.close().catch(() => undefined);
-  rmSync(handle.cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  try {
+    rmSync(handle.cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  } catch (error) {
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code !== "EBUSY" && code !== "ENOTEMPTY" && code !== "EPERM") {
+      throw error;
+    }
+  }
 }
 
 async function startTurnAndCollectEvents(

packages/server/src/server/agent/providers/claude-agent.integration.test.ts

@@ -8,9 +8,23 @@ import { query, type SDKUserMessage } from "@anthropic-ai/claude-agent-sdk";
 import type { AgentSession, AgentStreamEvent, ToolCallTimelineItem } from "../agent-sdk-types.js";
 import { findExecutable, isCommandAvailable } from "../../../utils/executable.js";
 import { withTimeout } from "../../../utils/promise-timeout.js";
+import { spawnProcess } from "../../../utils/spawn.js";
 import { ClaudeAgentClient } from "./claude-agent.js";
 import { streamSession } from "./test-utils/session-stream-adapter.js";
 
+type SpawnClaudeOptions = NonNullable<
+  Parameters<typeof query>[0]["options"]
+>["spawnClaudeCodeProcess"];
+
+const spawnClaudeForTest: SpawnClaudeOptions = (options) =>
+  spawnProcess(options.command, options.args, {
+    cwd: options.cwd,
+    env: options.env,
+    signal: options.signal,
+    stdio: ["pipe", "pipe", "pipe"],
+    shell: false,
+  });
+
 const logger = pino({ level: "silent" });
 const client = new ClaudeAgentClient({ logger });
 const hasClaudeCredentials =
@@ -157,7 +171,14 @@ async function createSession(params?: {
 
 async function cleanupSession(handle: { cwd: string; session: AgentSession }): Promise<void> {
   await handle.session.close().catch(() => undefined);
-  rmSync(handle.cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  try {
+    rmSync(handle.cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  } catch (error) {
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code !== "EBUSY" && code !== "ENOTEMPTY" && code !== "EPERM") {
+      throw error;
+    }
+  }
 }
 
 describe("ClaudeAgentSession integration", () => {
@@ -233,6 +254,7 @@ describe("ClaudeAgentSession integration", () => {
         includePartialMessages: false,
         settingSources: ["user", "project"],
         pathToClaudeCodeExecutable: claudeBinary,
+        spawnClaudeCodeProcess: spawnClaudeForTest,
       },
     });
 

packages/server/src/server/agent/providers/claude-sdk-behavior.test.ts

@@ -7,6 +7,20 @@ import path from "node:path";
 import { beforeAll, beforeEach, describe, expect, test } from "vitest";
 import { query, type SDKMessage, type SDKUserMessage } from "@anthropic-ai/claude-agent-sdk";
 import { findExecutable, isCommandAvailable } from "../../../utils/executable.js";
+import { spawnProcess } from "../../../utils/spawn.js";
+
+type SpawnClaudeOptions = NonNullable<
+  Parameters<typeof query>[0]["options"]
+>["spawnClaudeCodeProcess"];
+
+const spawnClaudeForTest: SpawnClaudeOptions = (options) =>
+  spawnProcess(options.command, options.args, {
+    cwd: options.cwd,
+    env: options.env,
+    signal: options.signal,
+    stdio: ["pipe", "pipe", "pipe"],
+    shell: false,
+  });
 
 class Pushable<T> implements AsyncIterable<T> {
   private queue: T[] = [];
@@ -53,6 +67,17 @@ function tmpCwd(): string {
   }
 }
 
+function rmCwd(cwd: string): void {
+  try {
+    rmSync(cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  } catch (error) {
+    const code = (error as NodeJS.ErrnoException).code;
+    if (code !== "EBUSY" && code !== "ENOTEMPTY" && code !== "EPERM") {
+      throw error;
+    }
+  }
+}
+
 function extractTextFromEvents(events: SDKMessage[]): string {
   let responseText = "";
   for (const event of events) {
@@ -104,6 +129,7 @@ describe("Claude SDK direct behavior", () => {
         includePartialMessages: true,
         permissionMode: "bypassPermissions",
         ...(claudeBinary ? { pathToClaudeCodeExecutable: claudeBinary } : {}),
+        spawnClaudeCodeProcess: spawnClaudeForTest,
         systemPrompt: {
           type: "preset",
           preset: "claude_code",
@@ -160,7 +186,7 @@ describe("Claude SDK direct behavior", () => {
       expect(sawResult || responseText.length === 0).toBe(true);
     } finally {
       input.end();
-      rmSync(cwd, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+      rmCwd(cwd);
     }
   }, 120000);
 });

packages/server/src/utils/spawn.launch-regression.test.ts

@@ -158,6 +158,8 @@ function makeLaunchFixture(ext: "exe" | "cmd" | "bat"): LaunchFixture {
 
   if (ext === "exe") {
     // Copy node.exe to <command>.exe and run our assert body via -e.
+    // The `--` separator stops Node from parsing userArgs as Node options
+    // (e.g. `--config` would otherwise trigger "bad option" → exit 9).
     // With -e there is no script slot, so process.argv = [node, ...userArgs] → slice(1).
     const binaryPath = path.join(root, `${command}.exe`);
     copyFileSync(process.execPath, binaryPath);
@@ -165,7 +167,7 @@ function makeLaunchFixture(ext: "exe" | "cmd" | "bat"): LaunchFixture {
       root,
       command,
       binaryPath,
-      args: ["-e", ASSERT_SCRIPT_BODY, ...userArgs],
+      args: ["-e", ASSERT_SCRIPT_BODY, "--", ...userArgs],
       expectedArgvJson,
       sliceFrom: 1,
     };