fix: hide spent rescue to prevent StateError crash; log per-attempt starts

Expose engine.rescueUsed getter and surface it through GameViewState so
the result overlay can omit the watch-ad FilledButton after a rescue has
been consumed, preventing a second tap from calling useContinue /
addExtraMoves and hitting their StateError guard. Give-up is promoted to
FilledButton when rescue is unavailable for clear affordance.

Also emit stageStart / endlessStart analytics in restart() so every
attempt (not just the first) is bracketed by a matching start event.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/ui/screens/game_screen.dart

@@ -391,33 +391,47 @@ class _GameScreenState extends ConsumerState<GameScreen>
       (GamePhase.stuck, StuckReason.outOfMoves) => (
           l10n.outOfMoves,
           [
-            FilledButton(
-              onPressed: () {
-                ref.read(analyticsProvider).rescueUsed(type: 'extra_moves');
-                notifier.addExtraMoves();
-              },
-              child: Text(l10n.plusFiveMoves),
-            ),
-            TextButton(
-              onPressed: notifier.declineAndLose,
-              child: Text(l10n.giveUp),
-            ),
+            if (!view.rescueUsed)
+              FilledButton(
+                onPressed: () {
+                  ref.read(analyticsProvider).rescueUsed(type: 'extra_moves');
+                  notifier.addExtraMoves();
+                },
+                child: Text(l10n.plusFiveMoves),
+              ),
+            if (view.rescueUsed)
+              FilledButton(
+                onPressed: notifier.declineAndLose,
+                child: Text(l10n.giveUp),
+              )
+            else
+              TextButton(
+                onPressed: notifier.declineAndLose,
+                child: Text(l10n.giveUp),
+              ),
           ],
         ),
       (GamePhase.stuck, _) => (
           l10n.boardFull,
           [
-            FilledButton(
-              onPressed: () {
-                ref.read(analyticsProvider).rescueUsed(type: 'continue');
-                notifier.useContinue();
-              },
-              child: Text(l10n.watchAdContinue),
-            ),
-            TextButton(
-              onPressed: notifier.declineAndLose,
-              child: Text(l10n.giveUp),
-            ),
+            if (!view.rescueUsed)
+              FilledButton(
+                onPressed: () {
+                  ref.read(analyticsProvider).rescueUsed(type: 'continue');
+                  notifier.useContinue();
+                },
+                child: Text(l10n.watchAdContinue),
+              ),
+            if (view.rescueUsed)
+              FilledButton(
+                onPressed: notifier.declineAndLose,
+                child: Text(l10n.giveUp),
+              )
+            else
+              TextButton(
+                onPressed: notifier.declineAndLose,
+                child: Text(l10n.giveUp),
+              ),
           ],
         ),
       (GamePhase.lost, _) when view.endless => (