feat: fix ramdisk file copies being incorrectly marked as directories, update man pages

kernel/src/Fs/Ramdisk.cpp

@@ -218,6 +218,13 @@ namespace Fs::Ramdisk {
     }
 
     int ReadDirAt(const char* path, const char** outNames, int maxEntries, int startIndex) {
+        // Reject outright if path names an existing regular file: without this,
+        // a file with no matching "path/..." children below falls through to
+        // the child-scan loop and returns 0 (empty), which callers that use
+        // ReadDir to test "is this a directory" (>= 0) misread as "yes".
+        int selfIdx = FindEntryByPath(path);
+        if (selfIdx >= 0 && !fileTable[selfIdx].isDirectory) return -1;
+
         // Normalize path: skip leading '/'
         if (path[0] == '/') path++;