fix(FSCommon): add nRF52 LittleFS empty-name guard to getFiles()

[Copilot]

getFiles() iterated with while (file) without the file.name()[0] guard that listDir() already uses to work around the Adafruit LittleFS nRF52 glue bug (issue 4395), where openNextFile() can return a File with an empty name. This could cause empty-name entries to be pushed into results and the loop to spin until maxCount was exhausted.

Changes

• src/FSCommon.cpp — updated the loop condition in getFiles() to match listDir():

// Before
while (file) {

// After
while (file && file.name()[0]) { // file.name()[0] check is a workaround for a bug in the Adafruit LittleFS nrf52 glue (see issue 4395)

🤝 Attestations

• I have tested that my proposed changes behave as described.
• I have tested that my proposed changes do not cause any obvious regressions on the following devices:
  • Heltec (Lora32) V3
  • LilyGo T-Deck
  • LilyGo T-Beam
  • RAK WisBlock 4631
  • Seeed Studio T-1000E tracker card
  • Other (please specify below)