✨ feat: collapsible flash sub-steps UI + erase_all checkbox

Rename erase_before_program → erase_all (semantics fix):
- erase_all: true  → -erase_all -erase_only (entire flash chip)
- erase_all: false → -erase_only (sectors matching BIN size)
Both options always erase; the checkbox controls scope, not yes/no.

UI additions:
- SubStepFrame widget: collapsible Erase/Program/Verify sub-steps
  with status dots (○/◉/●) and colored labels
- Automatically expands on Step 2 start, collapses on completion
- Phase and progress driven by real-time program_flash output parsing
- Checkbox label: '整片Flash擦除 (Erase entire flash)'

subprocess_utils.py phase detection:
- Parses 'Performing Erase/Program/Verify Operation' for phase transitions
- Emits 'phase' callbacks (erase/program/verify/done)
- Progress % tracked within current phase

config.yaml

@@ -1,10 +1,10 @@
 bootloader_bin_path: /home/ly0kos/work/Verify/FW/tftp_app/bootloader/bootloader_z100_800M.bin
 bootloader_bit_path: /home/ly0kos/work/Verify/FW/tftp_app/bootloader/pl_arm_wrapper_hw_platform_0/pl_arm_wrapper.bit
 bootloader_elf_path: /home/ly0kos/work/Verify/FW/tftp_app/bootloader/app.elf
-firmware_bin_path: /home/ly0kos/work/Verify/FW/V1.3.1.3.3_06_01_pmu_cpld_check/V1.3.1.3.3_06_01_pmu_cpld_check.bin
-flash_type: qspi-x4-single
-flash_model: s25fl256s1
 erase_before_program: true
+firmware_bin_path: /home/ly0kos/work/Verify/FW/V1.3.1.3.3_06_01_pmu_cpld_check/V1.3.1.3.3_06_01_pmu_cpld_check.bin
+flash_model: s25fl256s1
+flash_type: qspi-x4-single
 fsbl_elf_path: /home/ly0kos/work/Verify/FPGA/Xilinx/Z100/fsbl_qspi_bypass.elf
 inter_step_delay: 2
 ping_count: 3