Add IPMI FRU editor to Tools page

- New card "IPMI — FRU" on Tools page (device 0, in-band)
- Read: GET /api/tools/ipmi-fru → ipmitool fru print 0 → editable table
- Editable fields: chassis (part#, serial, extra), board (mfr, product, serial, part#),
  product (mfr, name, part#, version, serial); read-only fields displayed as text
- Write: POST /api/tools/ipmi-fru/write → task → backup to fru-backups/ → ipmitool fru edit per field
- Dirty tracking + Save (N changed) button, same UX as Supermicro DMI card

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

audit/internal/webui/task_runner.go

@@ -388,6 +388,12 @@ func executeTaskWithOptions(opts *HandlerOptions, t *Task, j *jobState, ctx cont
 			break
 		}
 		err = runSAADMIWriteTask(ctx, j, opts.ExportDir, t.params)
+	case "ipmi-fru-write":
+		if len(t.params.FRUChanges) == 0 {
+			err = fmt.Errorf("no changes provided")
+			break
+		}
+		err = runIPMIFRUWriteTask(ctx, j, opts.ExportDir, t.params)
 	default:
 		j.append("ERROR: unknown target: " + t.Target)
 		j.finish("unknown target")