debug: track ALL writes to Parquet files

CRITICAL FINDING from previous run:
- getPos() was NEVER called by Parquet/Hadoop!
- This eliminates position tracking mismatch hypothesis
- Bytes are genuinely not reaching our write() method

Added detailed write() logging to track:
- Every write call for .parquet files
- Cumulative totalBytesWritten after each write
- Buffer state during writes

This will show the exact write pattern and reveal:
A) If Parquet writes 762 bytes but only 684 reach us → FSDataOutputStream buffering issue
B) If Parquet only writes 684 bytes → Parquet calculates size incorrectly
C) Number and size of write() calls for a typical Parquet file

Expected patterns:
- Parquet typically writes in chunks: header, data pages, footer
- For small files: might be 2-3 write calls
- Footer should be ~78 bytes if that's what's missing

Next run will show EXACT write sequence.

other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java

@@ -149,6 +149,7 @@ public class SeaweedOutputStream extends OutputStream {
 
     @Override
     public void write(final int byteVal) throws IOException {
+        LOG.debug("[DEBUG-2024] ✍️ write(int): 1 byte, path={}", path);
         write(new byte[] { (byte) (byteVal & 0xFF) });
     }
 
@@ -166,6 +167,11 @@ public class SeaweedOutputStream extends OutputStream {
         }
 
         totalBytesWritten += length;
+        if (path.contains("parquet")) {
+            LOG.info("[DEBUG-2024] ✍️ write({} bytes): totalSoFar={} position={} bufferPos={}, file={}", 
+                    length, totalBytesWritten, position, buffer.position(), 
+                    path.substring(path.lastIndexOf('/') + 1));
+        }
 
         // System.out.println(path + " write [" + (outputIndex + off) + "," +
         // ((outputIndex + off) + length) + ")");