fix(controller,apiserver,xcecli): expose job CPU peak and efficiency to the apiserver and xcecli (bug-1736)

The controller computed run usage (CPU time, memory, CPU peak and
efficiency, LSF bjobs -l definitions) but the capnp Job struct had no
field for it, so the job pushed to the apiserver never carried it, and
snapshots (the same struct) dropped it: a job restored from a checkpoint
lost its accumulated usage.

- controller.capnp: Job.runUsage @13 (JobRunusage); old entries decode
  with no run usage.
- apiserver: map run_usage into JobInfo; max_mem, avg_mem, used_mem,
  cpu_time, peak_cpu, peak_cpu_time, peak_cpu_duration, mem_efficiency,
  avg_cpu_efficiency, peak_cpu_efficiency become queryable columns.
- xcecli: -o fields MAX_MEM, AVG_MEM, MEM_EFFICIENCY, CPU_PEAK,
  CPU_PEAK_DURATION, CPU_EFFICIENCY, CPU_PEAK_EFFICIENCY (CPU_TIME now
  renders too), and a MEMORY USAGE / CPU USAGE block in jobs list -l.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/frontend/apiserver/backend/convert.go

@@ -114,6 +114,20 @@ func cJobToModel(job *C.xce_job_t) *models.JobInfo {
 		}
 		r.submit = rd
 	}
+	if u := job.run_usage; u != nil {
+		r.runUsage = &rawRunUsage{
+			maxMem:            float64(u.max_mem),
+			avgMem:            float64(u.avg_mem),
+			usedMem:           float64(u.used_mem),
+			cpuTime:           int(u.cpu_time),
+			peakCPUTime:       int(u.peak_cpu_time),
+			peakCPUDuration:   int(u.peak_cpu_duration),
+			memEfficiency:     float64(u.mem_efficiency),
+			avgCPUEfficiency:  float64(u.avg_cpu_efficiency),
+			peakCPUEfficiency: float64(u.peak_cpu_efficiency),
+			peakCPU:           float64(u.peak_cpu),
+		}
+	}
 	if job.allocs != nil {
 		n := int(job.allocs.nhosts)
 		for i := 0; i < n; i++ {