fix(execute-command): return partial output on timeout/maxBuffer instead of throwing

When a command times out or exceeds the buffer limit, the route returns
partial stdout/stderr. Previously the handler threw an Error, discarding
that output. Now returns partial output with an error field so downstream
blocks can inspect it.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/sim/executor/handlers/execute-command/execute-command-handler.ts

@@ -44,6 +44,12 @@ export class ExecuteCommandBlockHandler implements BlockHandler {
     )
 
     if (!result.success) {
+      if (result.output) {
+        return {
+          ...result.output,
+          error: result.error || 'Command execution failed',
+        }
+      }
       throw new Error(result.error || 'Command execution failed')
     }