Refine app account panel theme and telemetry layout

[yvette-carlisle]

Summary

• refresh Decodex App glass/material surfaces immediately across light/dark appearance changes
• refine account panel surface contrast in dark and light mode
• merge account telemetry readouts into a compact unified matrix

Validation

• swift test --package-path apps/decodex-app
• git diff --check
• cargo make test-decodex-app-stage