The existing y_flip tests cover Device:R (symmetric two-pin) and Device:C
rotated 90° (still electrically symmetric). The original bug — a double
Y-flip in get_pin_location — was invisible on symmetric passives because
pin 1 and pin 2 are interchangeable; it only showed up on asymmetric
multi-pin ICs like RF_Module:ESP32-WROOM-32, where labels meant for pin 3
(EN) silently landed on pin 35 (TXD0).
This adds a third test using an inline 6-pin asymmetric symbol with pins
at both positive and negative library Y on both sides. It asserts every
pin lands at the formula-predicted (symbol_x + lib_px, symbol_y - lib_py)
position, with an explicit cross-check that lib +Y pins resolve *above*
the placement centre in schematic Y-down space.
No system-library dependency — the symbol is constructed inline so the
test runs anywhere pytest does.
Fixes#135
aff498ae76