RF_HandleEdgeInterrupt()'s software ping-pong toggle can leave P3IM0
parked in either edge direction while awake; Enter_Low_Power_Sleep()
never reset it, so sleep entry could randomly land on a direction that
misses the wake edge. Per the datasheet truth table (WO-04 2.9), only
edge modes support power-down wake, not level modes, so this forces a
known rising-edge state (matching RF_Init()'s own boot default) instead
of switching to level-triggered as originally requested. wo-05 updated
to record the deviation and rationale.
SGM_CTRL was turned on at the very start of LCD_Init(), before the
ST7789V register sequence and first frame ran, showing garbage/blank
content briefly on every boot. GPIO_Init() now forces backlight off at
power-on, LCD_Init() no longer touches it, and main() only turns it on
right before entering the main loop (after HomeApp's first frame is
drawn). Wakeup_Restore()'s existing on-then-reinit sequence is
untouched since it sets the level itself before calling LCD_Init().
Root cause found via datasheet: PxIM0/PxIM1 has no dual-edge mode, only
falling/rising/low-level/high-level. (IM1=1,IM0=1) was actually
high-level interrupt, refiring continuously for the whole high-pulse
duration (confirmed by scope: no real HF noise, and edge_count=0 when
P3.6 grounded). Fix: start in rising-edge mode, software-toggle to the
opposite edge on every trigger (ping-pong) to emulate true dual-edge
triggering, feeding exact edge direction into the incremental decode
state machine (no glitch filter needed). Also switch P3.6 idle bias
from pull-up to pull-down, since floating-high under the old high-level
mode caused the interrupt-storm boot issue; removed the now-conflicting
pull-up restore in Wakeup_Restore().
