Fix GPU model propagation, export filenames, PSU/service status, and chart perf

- nvidia.go: add Name field to nvidiaGPUInfo, include model name in
  nvidia-smi query, set dev.Model in enrichPCIeWithNVIDIAData
- pages.go: fix duplicate GPU count in validate card summary (4 GPU: 4 x …
  → 4 x … GPU); fix PSU UNKNOWN fallback from hw.PowerSupplies; treat
  activating/deactivating/reloading service states as OK in Runtime Health
- support_bundle.go: use "150405" time format (no colons) for exFAT compat
- sat.go / benchmark.go / platform_stress.go / sat_fan_stress.go: remove
  .tar.gz archive creation from export dirs — export packs everything itself
- charts_svg.go: add min-max downsampling (1400 pt cap) for SVG chart perf
- benchmark_report.go / sat.go: normalize GPU fallback to "Unknown GPU"

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

audit/internal/app/support_bundle.go

@@ -213,7 +213,7 @@ func BuildSupportBundle(exportDir string) (string, error) {
 
 	now := time.Now().UTC()
 	date := now.Format("2006-01-02")
-	tod := now.Format("15:04:05")
+	tod := now.Format("150405")
 	ver := bundleVersion()
 	model := serverModelForBundle()
 	sn := serverSerialForBundle()