fix: sync game state before auto-boss challenge (#102)

Auto-boss was calling the boss API directly without first flushing
pending game state to the server. This inlines a saveGame call (using
refs, matching the existing auto-save pattern) before the challenge so
the server sees up-to-date state, consistent with the manual challenge
flow.

apps/web/src/context/gameContext.tsx

@@ -1281,7 +1281,26 @@ export const GameProvider = ({
         if (availableBoss !== undefined) {
           const { id: bossId, name: bossName } = availableBoss;
           isAutoBossingReference.current = true;
-          void challengeBossApi({ bossId }).
+          const syncBeforeBoss
+            = stateReference.current !== null && !isSyncingReference.current
+              ? saveGame({
+                state: stateReference.current,
+                ...signatureReference.current === null
+                  ? {}
+                  : { signature: signatureReference.current },
+              }).then((response) => {
+                if (response.signature !== undefined) {
+                  signatureReference.current = response.signature;
+                  localStorage.setItem(
+                    "elysium_save_signature",
+                    response.signature,
+                  );
+                }
+              })
+              : Promise.resolve();
+          void syncBeforeBoss.then(async() => {
+            return await challengeBossApi({ bossId });
+          }).
             then((result) => {
               setState((previous) => {
                 if (previous === null) {