Improve os detection and file existance checks

core/src/main/java/io/xpipe/core/impl/FileStore.java

@@ -82,7 +82,7 @@ public class FileStore extends JacksonizedValue implements FilenameStore, Stream
 
     @Override
     public boolean canOpen() throws Exception {
-        return fileSystem.createFileSystem().open().exists(path);
+        return fileSystem.createFileSystem().open().fileExists(path);
     }
 
     @Override

core/src/main/java/io/xpipe/core/process/ShellDialect.java

@@ -123,7 +123,7 @@ public interface ShellDialect {
 
     String getFileDeleteCommand(String file);
 
-    String getFileExistsCommand(String file);
+    CommandControl createFileExistsCommand(ShellControl sc, String file);
 
     String getFileTouchCommand(String file);
 

core/src/main/java/io/xpipe/core/store/ConnectionFileSystem.java

@@ -76,9 +76,9 @@ public class ConnectionFileSystem implements FileSystem {
     }
 
     @Override
-    public boolean exists(String file) throws Exception {
-        try (var pc = shellControl.command(proc -> proc.getShellDialect()
-                        .getFileExistsCommand(file)).complex()
+    public boolean fileExists(String file) throws Exception {
+        try (var pc = shellControl.getShellDialect()
+                        .createFileExistsCommand(shellControl, file).complex()
                 .start()) {
             return pc.discardAndCheckExit();
         }

core/src/main/java/io/xpipe/core/store/FileSystem.java

@@ -51,7 +51,7 @@ public interface FileSystem extends Closeable, AutoCloseable {
 
     OutputStream openOutput(String file) throws Exception;
 
-    public boolean exists(String file) throws Exception;
+    public boolean fileExists(String file) throws Exception;
 
     public  void delete(String file) throws Exception;
 

core/src/main/java/io/xpipe/core/util/XPipeSession.java

@@ -42,6 +42,7 @@ public class XPipeSession {
                 : UuidHelper.parse(() -> Files.readString(sessionFile)).orElse(UUID.randomUUID());
 
         try {
+            //TODO: People might move their page file to another drive
             if (OsType.getLocal().equals(OsType.WINDOWS)) {
                 var pf = Path.of("C:\\pagefile.sys");
                 BasicFileAttributes attr = Files.readAttributes(pf, BasicFileAttributes.class);

core/src/main/java/io/xpipe/core/util/XPipeTempDirectory.java

@@ -23,7 +23,7 @@ public class XPipeTempDirectory {
         var base = proc.getOsType().getTempDirectory(proc);
         var dir = FileNames.join(base, "xpipe");
 
-        if (!proc.executeBooleanSimpleCommand(proc.getShellDialect().getFileExistsCommand(dir))) {
+        if (!proc.getShellDialect().createFileExistsCommand(proc, dir).executeAndCheck()) {
             proc.executeSimpleCommand(proc.getShellDialect().getMkdirsCommand(dir),
                     "Unable to access or create temporary directory " + dir);