SAFETY-136: a gentler loop on a slow meter until the last move shows

On a meter whose readings come 4 s or more apart, the loop runs at half its
gain after a move of 150 W or more, until the meter has fallen by half of the
move or 2 cycles have passed. With readings 10 s late on a 5 s meter the export
falls 44 % over oven, kettle and hob, owner shape, steps; 1-2 s meters are
untouched.

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

goodwe_controller/app/ctl_cycle.py

@@ -734,15 +734,21 @@ class CycleMixin:
             # TEL-10. ⚠️ ONE NAME FOR THE COMMAND THE LOOP WAS MEASURED
             # AGAINST. (DECISIONS/MAIN-orchestration-archive.md)
             loop_prev = self.target
+            # SAFETY-95: a drain's tail is not the loop's to chase.
+            # OPT-15: `loop_grid` is the grid, or the target while a run
+            # edge is held.
+            grid_in = (self._drain_grid_w(_live96) if self._drain_tail
+                       else loop_grid)
+            # SAFETY-136: on a slow meter, a gentler loop until the last move
+            # shows.
+            slow_meter = self.settle.slow()
+            if moved or mode_trade:
+                self.settle.reset()
             decision = compute(
                 prev_w=loop_prev,
-                # SAFETY-95: a drain's tail is not the loop's to chase.
-                # OPT-15: `loop_grid` is the grid, or the target while a run
-                # edge is held.
-                grid_w=(self._drain_grid_w(_live96) if self._drain_tail
-                        else loop_grid),
+                grid_w=grid_in,
                 actual_w=site_batt,
-                tuning=self.tuning,
+                tuning=self.settle.tuning(self.tuning, grid_in, slow_meter),
                 sat_count=self.sat_count,
                 i_w=self.i_w,
                 # SAFETY-52 at one inverter only: with several, OPT-09's pack
@@ -772,6 +778,7 @@ class CycleMixin:
                 self.log_event(f"saturation freeze ({self.target:.0f} W vs "
                                f"{site_batt:.0f} W)",
                                hint=messages.hint("not_keeping_up"))
+            self.settle.moved(grid_in, loop_prev, decision.target_w, slow_meter)
             self.sat_count = decision.sat_count
             self.i_w = decision.i_w
             self.loop_w = decision.target_w
@@ -811,6 +818,7 @@ class CycleMixin:
         else:
             # Stopped or blind: no accumulation may survive the outage.
             self.i_w = 0.0
+            self.settle.reset()
             self.loop_w = None
             self._live_was = frozenset(_live96)
             # TEL-10, and it is the same zero the line above writes rather than