feat: disable auto-save, add Save to Files button, accept all file types in library

- Disabled auto-save of processed files to library (worker no longer
  calls autoSaveToLibrary)
- Added "Save to Files" button in the review panel for explicit saving
- Files library upload area now accepts all file types, not just images
- Removed "Drop images here" hardcoded text, replaced with i18n
- Removed image-only file filter from library upload

apps/api/src/jobs/worker.ts

@@ -238,15 +238,8 @@ async function processToolJob(job: Job<ToolJobData>): Promise<ToolJobResult> {
     // Generate preview for non-browser-previewable formats
     const previewRef = await generatePreview(resultBuffer, resultContentType, jobId, inputBuffer);
 
-    // Auto-save to user file library
-    const savedFileId = await autoSaveToLibrary({
-      fileId: data.fileId,
-      userId: data.userId,
-      buffer: resultBuffer,
-      outName,
-      contentType: resultContentType,
-      toolId: data.toolId,
-    });
+    // No auto-save -- users save to library explicitly via the UI
+    const savedFileId: string | undefined = undefined;
 
     const durationMs = Date.now() - startTime;