✨ feat: flash phase tracking, erase checkbox, flash_model config

Step 2 UI now shows real-time flash operation phases parsed from program_flash output:
- Erase: "Performing Erase Operation..." → sf erase → Erased: OK
- Program: "Performing Program Operation..." → write blocks 0%→100%
- Verify: "Performing Verify Operation..." → read+cmp 0%→100%

Configuration additions:
- erase_before_program checkbox: controls whether to pre-erase before programming
- flash_model: chip type for capacity reference (s25fl256s1 = 32 MiB)

subprocess_utils.py now emits 'phase' callbacks (erase/program/verify/done)
detected from program_flash output transitions.

config.yaml

@@ -3,6 +3,8 @@ bootloader_bit_path: /home/ly0kos/work/Verify/FW/tftp_app/bootloader/pl_arm_wrap
 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
 fsbl_elf_path: /home/ly0kos/work/Verify/FPGA/Xilinx/Z100/fsbl_qspi_bypass.elf
 inter_step_delay: 2
 ping_count: 3
@@ -10,15 +12,14 @@ ping_timeout: 5
 reboot_timeout: 30
 serial_baudrate: 115200
 serial_port: /dev/ttyUSB0
-tftp_upload_name: z7bin
-uart_delay: 3
-inter_step_delay: 2
 step_timeouts:
+  bitstream: 60
   check_env: 30
+  elf_download: 60
   flash_erase: 120
   flash_program: 600
-  bitstream: 60
-  elf_download: 60
   tftp_reboot: 120
-vitis_path: ""
+tftp_upload_name: z7bin
+uart_delay: 3
+vitis_path: ''
 zynq_ip: 192.168.100.11