SAFETY-136 round 2: tests for override and direction, true wording

F1 the on-change case is tested as slow, F2 override and direction checks,
F3 the 3.75 s rule in the texts, F4 the quarter figures and the live note.
No behaviour change.

Co-Authored-By: Claude <noreply@anthropic.com>

goodwe_controller/app/settle.py

@@ -1,10 +1,10 @@
 """SAFETY-136: on a slow meter, follow the meter gently until the last move shows.
 
-A meter whose readings come 4 s or more apart, read through Home Assistant, can
-be 10-15 s late. The loop then answers the same error again at each cycle
+A meter whose usual gap between readings is over 3.75 s (a 4-5 s meter), read
+through Home Assistant, can be 10-15 s late. The loop then answers the same error again at each cycle
 and overshoots. After a move of MOVE_W or more the loop therefore runs at
 WAIT_SHARE of its gain until the meter has fallen SHOWN of the move, or for at
-most WAIT_CYCLES cycles. Off for a meter under 4 s, so those sites run as
+most WAIT_CYCLES cycles. Off for a meter with a usual gap of 3.75 s or less, so those sites run as
 before. DECISIONS/SAFETY-136-slow-meter-settle.md.
 """