fix: tolerate OpenSCAD CGAL warnings if output file is created

OpenSCAD 2021.01 (Debian stable) has CGAL geometry bugs that cause
non-zero exit status when processing complex STL operations, but it
still produces valid output files.

Instead of failing the job when OpenSCAD exits with non-zero status,
we now check if the output file was created. If it exists, we proceed
with the job. Only if the file is missing do we treat it as a failure.

This allows 3D model generation to work on production despite the
older OpenSCAD version's CGAL warnings.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/src/lib/3d-printing/jobManager.ts

@@ -122,18 +122,29 @@ export class JobManager {
       console.log(`Executing: ${cmd}`)
 
       // Execute OpenSCAD (with 60s timeout)
+      // Note: OpenSCAD may exit with non-zero status due to CGAL warnings
+      // but still produce valid output. We'll check file existence afterward.
       try {
         await execAsync(cmd, {
           timeout: 60000,
           cwd: join(process.cwd(), 'public', '3d-models'),
         })
       } catch (execError) {
-        // Log detailed error information
-        console.error(`OpenSCAD execution failed:`, execError)
-        if (execError instanceof Error) {
-          throw new Error(`OpenSCAD error: ${execError.message}`)
+        // Log the error but don't throw yet - check if output was created
+        console.warn(`OpenSCAD reported errors, but checking if output was created:`, execError)
+
+        // Check if output file exists despite the error
+        try {
+          await readFile(outputPath)
+          console.log(`Output file created despite OpenSCAD warnings - proceeding`)
+        } catch (readError) {
+          // File doesn't exist, this is a real failure
+          console.error(`OpenSCAD execution failed and no output file created:`, execError)
+          if (execError instanceof Error) {
+            throw new Error(`OpenSCAD error: ${execError.message}`)
+          }
+          throw execError
         }
-        throw execError
       }
 
       job.progress = 'Finalizing...'