- Rename bit_path -> bootloader_bit_path for clarity
- Rename elf_path -> bootloader_elf_path for clarity
- Split single bin_path into bootloader_bin_path (flash) and
firmware_bin_path (TFTP upload)
- Reorder Configuration panel: BIT -> ELF -> Bootloader BIN ->
Firmware BIN
- Update display names with file extensions and context labels
- Update all step references (Step 2 flash, Step 3 bootloader,
Step 4 TFTP) to use new field names