style: apply rustfmt across all crates and demos

Consistent formatting pass: line wrapping, import sorting, trailing
whitespace removal, let-chain indentation, merged derive attributes,
and unsafe block reformatting.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

crates/training/rtx-compress/src/arrow_integration.rs

@@ -100,7 +100,8 @@ impl ArrowCompressor {
         // Simplified compression - just store array info
         let mut compressed_data = Vec::new();
         compressed_data.extend_from_slice(&array.len().to_le_bytes());
-        compressed_data.extend_from_slice(&(std::ptr::from_ref(array.data_type()) as usize).to_le_bytes());
+        compressed_data
+            .extend_from_slice(&(std::ptr::from_ref(array.data_type()) as usize).to_le_bytes());
 
         Ok(CompressedArrowArray {
             compressed_data,
@@ -257,7 +258,11 @@ impl StreamingCompressor {
     pub fn finalize(self) -> Result<CompressedStream> {
         let metadata = StreamMetadata {
             num_batches: self.batches.len(),
-            total_rows: self.batches.iter().map(arrow::array::RecordBatch::num_rows).sum(),
+            total_rows: self
+                .batches
+                .iter()
+                .map(arrow::array::RecordBatch::num_rows)
+                .sum(),
             compression_ratio: 3.5, // Placeholder
         };