Fixes found during real hardware test:
bitstream_programmer.py:
- _program_with_xsct: use TCL file instead of xsct -eval (quit→exit fix)
- _run_elf_with_xsct: add reconnect + source ps7_init.tcl after PL config,
use target ID 2 instead of name filter, TCL file instead of -eval
- _find_ps7_init_tcl: auto-detect ps7_init.tcl from BIT file directory
- run_elf: remove Vivado fallback (program_hw_cpu is xsct, not Vivado)
- Remove dead _run_elf_with_vivado (Vivado HM can't program PS CPU)
flash_programmer.py:
- wipe_flash: -erase_only without -erase_all (s25fl256s1 compat fix)