Apply rustfmt to entire workspace

Runs cargo fmt --all; all 573 tests still passing, clippy still clean.
No logic changes — formatting only.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

crates/clawhdf5-onion/tests/proptest_versioned.rs

@@ -48,7 +48,11 @@ struct Round {
 
 fn arb_round() -> impl Strategy<Value = Round> {
     (any::<bool>(), 0usize..8usize, 1u8..=255u8).prop_map(|(create_branch, branch_idx, fill)| {
-        Round { create_branch, branch_idx, fill }
+        Round {
+            create_branch,
+            branch_idx,
+            fill,
+        }
     })
 }
 
@@ -72,10 +76,7 @@ fn make_vf() -> (TempDir, std::path::PathBuf, VersionedFile) {
 /// Apply `rounds` to `vf`, returning a Vec of `(revision_number, expected_page_bytes)`.
 ///
 /// `branches` starts as `["main"]` and grows as new branches are created.
-fn apply_rounds(
-    vf: &mut VersionedFile,
-    rounds: &[Round],
-) -> Vec<(u64, Vec<u8>)> {
+fn apply_rounds(vf: &mut VersionedFile, rounds: &[Round]) -> Vec<(u64, Vec<u8>)> {
     let mut branches: Vec<String> = vec!["main".to_string()];
     let mut expectations: Vec<(u64, Vec<u8>)> = Vec::new();
     let mut branch_counter: usize = 0;
@@ -124,7 +125,8 @@ fn verify_expectations(
         prop_assert_eq!(
             &actual[..page_end],
             expected.as_slice(),
-            "revision {}: page 0 mismatch", rev
+            "revision {}: page 0 mismatch",
+            rev
         );
     }
     Ok(())