fix(webui): trust IPMI FRU readback over ipmitool's exit code

`ipmitool fru edit` frequently exits non-zero after a field resize
(shrinking/growing a string shifts every later offset in the FRU
record) even though the write itself landed correctly on the BMC -
the failure is in ipmitool's own post-write re-parse, not the write.
bee was treating that exit code as authoritative and marking the task
failed even when the field was actually written.

runIPMIFRUWriteTask now re-reads the FRU on a non-zero exit and
compares the target field's actual value before deciding the task
failed, logging which path it took either way.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

audit/internal/webui/ipmi_fru.go

@@ -210,8 +210,37 @@ func runIPMIFRUWriteTask(ctx context.Context, j *jobState, exportDir string, p t
 		j.append(fmt.Sprintf("Setting %s (%s %d) = %q", c.Name, c.Area, c.Index, c.Value))
 		cmd := exec.CommandContext(ctx, "ipmitool", "fru", "edit", "0", "field", c.Area, fmt.Sprintf("%d", c.Index), c.Value)
 		if err := streamCmdJob(j, cmd); err != nil {
-			return fmt.Errorf("fru edit %s %d: %w", c.Area, c.Index, err)
+			// ipmitool's `fru edit` frequently exits non-zero after a field
+			// resize (shrinking/growing a string shifts every later offset in
+			// the FRU record) even though the write itself landed correctly -
+			// the failure is in ipmitool's own post-write re-parse, not the
+			// BMC write. Read the FRU back and trust the BMC's own data over
+			// ipmitool's exit code before declaring the task failed.
+			ok, verifyErr := verifyFRUField(ctx, c.Area, c.Index, c.Value)
+			if verifyErr != nil {
+				j.append("Readback verification failed: " + verifyErr.Error())
+				return fmt.Errorf("fru edit %s %d: %w", c.Area, c.Index, err)
+			}
+			if !ok {
+				return fmt.Errorf("fru edit %s %d: %w", c.Area, c.Index, err)
+			}
+			j.append(fmt.Sprintf("ipmitool exited with an error, but readback confirms %s %d was written correctly - continuing", c.Area, c.Index))
 		}
 	}
 	return nil
 }
+
+// verifyFRUField re-reads the FRU and checks whether the field at area/index
+// already holds want, independent of any exit code from a prior edit.
+func verifyFRUField(ctx context.Context, area string, index int, want string) (bool, error) {
+	out, err := exec.CommandContext(ctx, "ipmitool", "fru", "print", "0").CombinedOutput()
+	if err != nil {
+		return false, fmt.Errorf("fru print: %w", err)
+	}
+	for _, f := range parseFRUOutput(string(out)) {
+		if f.Area == area && f.Index == index {
+			return f.Value == want, nil
+		}
+	}
+	return false, nil
+}