chore(tts): suppress stderr output after initial setup

src/tts.ts

@@ -62,6 +62,14 @@ async function main() {
 
   const home = os.homedir();
   const cwd = path.join(home, ".ttsc");
+  const firstRun = await (async () => {
+    try {
+      await fs.access(cwd, fs.constants.F_OK);
+      return false;
+    } catch {
+      return true;
+    }
+  })();
 
   if (editContent) {
     const file = path.join(cwd, "input.txt");
@@ -90,7 +98,7 @@ async function main() {
     cwd,
     input,
     stdout: "pipe",
-    stderr: "inherit",
+    stderr: firstRun ? "inherit" : "ignore",
   })`uv run -- python -u main.py`;
 
   if (!waitAndCombine) {