style: apply rustfmt to establish clean baseline before refactor

Pre-refactor baseline state:
- 79 lib tests + 3 integration tests pass (1 integration test #[ignore])
- cargo clippy --all-targets -- -D warnings clean
- cargo build --release clean

No semantic changes; only rustfmt drift correction across 6 files.

src/bin/vaapi_import_bench.rs

@@ -419,9 +419,7 @@ fn import_frame(
     // carries a valid DMA-BUF fd and metadata from PipeWire for the duration of the call.
     // SAFETY: frames_ctx is a valid VAAPI frames context; `frame` carries the
     // DMA-BUF metadata read by the function.
-    unsafe {
-        import_dma_buf_to_vaapi(frames_ctx.as_ptr(), frame)
-    }
+    unsafe { import_dma_buf_to_vaapi(frames_ctx.as_ptr(), frame) }
 }
 
 fn build_gpu_filter_graph(
@@ -936,9 +934,7 @@ fn main() -> Result<()> {
     // `first_frame` is the PipeWire-formatted PwDmaBufFrame whose metadata the
     // function reads directly. See that function's own SAFETY contract for the
     // full rationale.
-    let vaapi_frame = unsafe {
-        import_dma_buf_to_vaapi(frames_ctx.as_ptr(), &first_frame)
-    };
+    let vaapi_frame = unsafe { import_dma_buf_to_vaapi(frames_ctx.as_ptr(), &first_frame) };
 
     match &vaapi_frame {
         Ok(_) => {