[GSD-12906] `zesPowerGetEnergyCounter()` returns near-zero energy values periodically on idle Intel Arc Pro B70/B60 — possible counter wrap

### Environment

| Node | GPU SKU | Kernel | compute-runtime (`libze-intel-gpu1`) | L0 loader (`libze1`) | TW spikes |
|---|---|---|---|---|---|
| node-A | B70 (0x8086:E223) | 6.17.0-35-generic | 26.09.37435.12 | 1.28.0 | 49 |
| node-C | B70 (0x8086:E223) | 6.17.0-1009-intel | 26.09.37435.12 | 1.28.0 | 2 |
| node-D | B60 | 6.14.0-1011-intel | 25.40.35563.10 | 1.26.2 | 17 |
| node-B | B70 (0x8086:E223) | 6.17.0-1009-intel | 26.18.38308.1 | 1.28.2 | 0 |

OS: Ubuntu 24.04 | xpumanager: 1.3.5-20251216 | Monitoring: 54 hrs, all nodes idle (0% GPU util)

### Observed behavior
`zesPowerGetEnergyCounter()` periodically returns energy values of ~100–300 J on GPU cards that have been continuously idle. The sysfs `hwmon energy*_input` counter for the same card at the same moment continues accumulating normally, confirming the hardware energy is intact.

xpumd reads the L0 counter every ~5s and computes power as `ediff / tdiff`. When the counter drops to ~200 J from ~22 MJ, the subtraction underflows as uint64, producing a ~3.69 TW result reported via `hw_power_watts`.

### Captured values at spike moment

| Time (UTC) | GPU (BDF) | `zesPowerGetEnergyCounter` (L0, power-1) | sysfs `energy1_input` | `hw_power_watts` |
|---|---|---|---|---|
| 2026-06-09 19:44:10 | node-A `0001:6b:00.0` | **209.8 J** | **22,543,283.9 J** | 3,688,785,853,643 W |
| 2026-06-09 22:02:11 | node-A `0001:91:00.0` | **173.4 J** | **23,329,654.5 J** | 3,690,483,216,906 W |

### Statistics (54-hour window)
- L0 counter resets: **345**
- TW spike events: **68**
- sysfs counter drops (node-C only): **67**

Related: intel/xpumanager#130