Unify window presentation and frame-driven shell motion

Share window geometry across overview, resize snapshots and retained closes. Advance close handoffs and group retained rendering by stacking position.

Drive shell motion from surface frames, reuse settled widget content, and synchronize notification materials with each card's fade. Replace physical config keys with duration and bounce, and update documentation and regression coverage.

scripts/tests/test_overview_damage_isolated.py

@@ -72,8 +72,17 @@ class OverviewDamageTest(unittest.TestCase):
                 # The first report includes time before this call. The second
                 # covers a full five seconds of the requested stationary scene.
                 count = len(reports())
-                wait_for(lambda: len(reports()) >= count + 2)
-                return reports()[-1]
+                for attempt in range(3):
+                    wait_for(lambda: len(reports()) >= count + 2)
+                    lines = log_path.read_text().splitlines()
+                    boundaries = [index for index, line in enumerate(lines)
+                                  if "render performance" in line]
+                    interval = lines[boundaries[-2] + 1:boundaries[-1]]
+                    if not any("ferese::nested_input:" in line for line in interval):
+                        return reports()[-1]
+                    print("Discarding interval with host input; waiting for a quiet interval", flush=True)
+                    count = len(boundaries) - 1
+                self.fail("No input-free interval for the stationary overview check")
 
             def assert_quiet(label, report):
                 print(label + ":", report, flush=True)