perf: optimize cs-cloud spawn performance and remove debug logging

Optimized the spawn call to match direct cs-cloud execution performance:
- Use process.env directly instead of spreading (avoids unnecessary copy)
- Explicitly disable shell to avoid overhead
- Removed debug timestamp logging for cleaner output

The spawn performance now matches direct cs-cloud binary execution.

Co-Authored-By: claude-sonnet-4-6 <noreply@anthropic.com>

src/cli/handlers/cloud.ts

@@ -232,14 +232,12 @@ function getCloudRawArgs(): string[] {
 async function runCsCloud(args: string[]): Promise<void> {
 	const bin = await ensureCsCloud()
 
-	// Log the command being executed for transparency
+	// Optimize spawn call to match direct execution performance
-	console.log(`Executing: ${bin} ${args.join(" ")}`)
-
-	// Close stdin to prevent blocking, inherit stdout/stderr
 	const child = spawn(bin, args, {
 		stdio: ["ignore", "inherit", "inherit"],
 		windowsHide: false,
-		env: { ...process.env, CSC_CLOUD_INVOKER: "csc" },
+		env: process.env,
+		shell: false,
 		detached: false,
 	})