feat(all): add hunting and events, commerce and rewards, binary calendars, GameData caching and login diagnostics

Implement hunting AP and progress, event tasks, exchanges, games, stories and actions; connect battle and reward handling.

Add CashShop plugin and installation, server purchases and entitlements, recharge rules and plugin version metadata.

Distribute binary calendars independently; cache GameData in memory and fix single-connection query deadlocks.

Improve automatic login and recovery diagnostics; document configuration and release flows.

go/internal/server/world/hunting_test.go

@@ -0,0 +1,39 @@
+package world
+
+import (
+	"testing"
+
+	"bd2server/internal/server/wire"
+)
+
+type fakeHuntingGround struct {
+	calls []int
+	row   []byte
+}
+
+func (h *fakeHuntingGround) EnsureForPack(pack int) ([]byte, error) {
+	h.calls = append(h.calls, pack)
+	return h.row, nil
+}
+
+func TestPackLoadRestoresActualHuntingState(t *testing.T) {
+	s := testService()
+	h := &fakeHuntingGround{row: wire.AppendVarint(nil, 2, 91)}
+	if err := s.AttachHuntingGround(h); err != nil {
+		t.Fatal(err)
+	}
+	out, err := s.packInfoFor(s.seed.PackID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	b, ok, err := wire.Bytes(out, 12)
+	if err != nil || !ok {
+		t.Fatalf("ground missing: %v", err)
+	}
+	if id, _, _ := wire.Varint(b, 2); id != 91 {
+		t.Fatalf("seed placeholder replaced state: %d", id)
+	}
+	if len(h.calls) != 1 || h.calls[0] != s.seed.PackID {
+		t.Fatal("wrong loaded pack")
+	}
+}