wallet: Use fsbridge::ifstream to fix Windows path issue

Author: ken2812221

src/fs.cpp

@@ -160,6 +160,7 @@ static std::string openmodeToStr(std::ios_base::openmode mode)
 void ifstream::open(const fs::path& p, std::ios_base::openmode mode)
 {
     close();
+    mode |= std::ios_base::in;
     m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
     if (m_file == nullptr) {
         return;
@@ -183,6 +184,7 @@ void ifstream::close()
 void ofstream::open(const fs::path& p, std::ios_base::openmode mode)
 {
     close();
+    mode |= std::ios_base::out;
     m_file = fsbridge::fopen(p, openmodeToStr(mode).c_str());
     if (m_file == nullptr) {
         return;

src/wallet/walletutil.cpp

@@ -35,7 +35,7 @@ static bool IsBerkeleyBtree(const fs::path& path)
     boost::system::error_code ec;
     if (fs::file_size(path, ec) < 4096) return false;
 
-    fs::ifstream file(path.string(), std::ios::binary);
+    fsbridge::ifstream file(path, std::ios::binary);
     if (!file.is_open()) return false;
 
     file.seekg(12, std::ios::beg); // Magic bytes start at offset 12