fix(server): guard paseo:ready IPC behind PASEO_SUPERVISED env var

The process.send check alone was insufficient because vitest also runs
workers with IPC channels. Now the supervisor sets PASEO_SUPERVISED=1
on the worker env, and bootstrap checks for it before sending.

packages/server/scripts/supervisor-entrypoint.ts

@@ -76,7 +76,7 @@ async function main(): Promise<void> {
   const config = parseConfig(process.argv.slice(2));
   const workerEntry = config.devMode ? resolveDevWorkerEntry() : resolveWorkerEntry();
   const workerExecArgv = resolveWorkerExecArgv(workerEntry);
-  const workerEnv: NodeJS.ProcessEnv = { ...process.env };
+  const workerEnv: NodeJS.ProcessEnv = { ...process.env, PASEO_SUPERVISED: "1" };
   const packagedNodeEntrypointRunner =
     process.env.ELECTRON_RUN_AS_NODE === "1"
       ? resolvePackagedNodeEntrypointRunnerPath(fileURLToPath(import.meta.url))

packages/server/src/server/bootstrap.ts

@@ -691,7 +691,7 @@ export async function createPaseoDaemon(
               );
             }
 
-            if (typeof process.send === "function") {
+            if (typeof process.send === "function" && process.env.PASEO_SUPERVISED === "1") {
               process.send({
                 type: "paseo:ready",
                 listen: