refactor(media): share fileExists

src/media-understanding/runner.ts

@@ -32,6 +32,7 @@ import {
   DEFAULT_IMAGE_MODELS,
 } from "./defaults.js";
 import { isMediaUnderstandingSkipError } from "./errors.js";
+import { fileExists } from "./fs.js";
 import { extractGeminiResponse } from "./output-extract.js";
 import {
   buildMediaUnderstandingRegistry,
@@ -175,18 +176,6 @@ async function hasBinary(name: string): Promise<boolean> {
   return Boolean(await findBinary(name));
 }
 
-async function fileExists(filePath?: string | null): Promise<boolean> {
-  if (!filePath) {
-    return false;
-  }
-  try {
-    await fs.stat(filePath);
-    return true;
-  } catch {
-    return false;
-  }
-}
-
 async function probeGeminiCli(): Promise<boolean> {
   const cached = geminiProbeCache.get("gemini");
   if (cached) {