v2.7.18 | LUI v0.2

Optimize node list rendering with simplified paging and longer cache TTL

• Introduce rawCount variable to track nodeDB size separately from filtered list
  size (totalEntries), eliminating naming ambiguity and potential bugs

• Add locationScreen state tracking to infinite scroll logic, ensuring scroll
  viewport resets when switching between modes (Last Heard vs Distance/Bearings)

• Remove complex infinite scroll infrastructure in favor of simple direct paging:

  • Replace infiniteScroll_updateViewport() with direct calculation
  • Remove infiniteScroll_topNum/bottomNum/resetState/updateRunning tracking
  • Eliminate cachedDrawList intermediate buffer
  • Render directly from cached filtered list using startIndex/endIndex math

• Simplify render loop: calculate page slice once, iterate directly through
  allNodesList subset without additional buffering or state management

• Increase cache TTL from 2000ms to 5000ms for better efficiency on T-Deck:

  • Reduces per-frame cache invalidation checks and allocations
  • Still catches position/status updates within reasonable window
  • Trade-off: distance/bearing updates appear within 5s instead of 2s

Benefits:

• Fewer CPU cycles per frame (no complex viewport math)
• Reduced memory churn (no intermediate drawList allocations)
• Cleaner, more maintainable code with fewer state variables
• Better performance on resource-constrained ESP32 devices