sessiond: record the wake, so the trail can tell it from nothing

apply_gesture's dark-panel branch returned Unblank+Restore without a
record_decision, while the blank branch records panel-off or
lock-before-blank. The trail showed 'button-gesture recognised' and then
silence, so a press that woke the panel and a press that was swallowed
left identical evidence — which is the one question anyone debugging a
dark phone is asking.

src/sessiond/device_state.rs

@@ -1628,6 +1628,16 @@ impl DeviceStateMachine {
             // `Restore` puts back the brightness the dim captured rather than a
             // guessed floor — see the comment on that capture.
             self.blank_requested = false;
+            // Recorded, because the blank branch below records and this one did
+            // not: the trail showed `button-gesture … recognised` and then
+            // silence, so "the press woke it" and "the press did nothing" were
+            // the same entry. A trail that cannot tell those apart is the one
+            // question anyone debugging a dark phone is actually asking.
+            self.record_decision(
+                "panel-on",
+                serde_json::json!({ "button": "power", "gesture": "tap" }),
+                "a tap on a dark panel is a wake",
+            );
             return vec![Action::Unblank, Action::Restore];
         }
         self.request_blank(