JTAG: Start hw_server explicitly (Windows needs it), then run Vivado TCL with Popen + line-by-line stdout streaming via callback so user can see Vivado progress in real-time (not just on failure). COM: Remove normalize_port — pyserial >= 3.0 handles COM>=10 prefix internally. The manual \\.\ prefix was causing PermissionError(13) on Windows where pyserial's own handling conflicted.