style: format the whole tree with cargo fmt (stock defaults, #35)

One-time, mechanical reformat — no functional changes. The tree was not
rustfmt-clean (~1800 hunks across ~100 files); this brings it to stock
`cargo fmt` defaults so a `cargo fmt --check` CI gate can follow.
Behaviour-preserving: 2509 pass / 0 fail / 1 ignored (unchanged baseline),
clippy clean. A .git-blame-ignore-revs entry follows so `git blame`
skips this commit.

tests/typing_surface/create_table.rs

@@ -83,25 +83,16 @@ fn after_pk_space_with_col_name_typed_expects_paren() {
 #[test]
 fn after_paren_expects_type_candidates() {
     let schema = schema_empty();
-    let a = assess_at_end(
-        "create table Customers with pk Code(",
-        &schema,
-    );
+    let a = assess_at_end("create table Customers with pk Code(", &schema);
     assert!(matches!(a.state, InputState::IncompleteAtEof));
-    assert_candidate_present(
-        &a,
-        &["text", "int", "serial", "shortid", "bool"],
-    );
+    assert_candidate_present(&a, &["text", "int", "serial", "shortid", "bool"]);
     crate::snap!("after_paren", a);
 }
 
 #[test]
 fn create_table_with_explicit_pk_parses() {
     let schema = schema_empty();
-    let a = assess_at_end(
-        "create table Customers with pk Code(text)",
-        &schema,
-    );
+    let a = assess_at_end("create table Customers with pk Code(text)", &schema);
     assert!(matches!(a.state, InputState::Valid));
     crate::snap!("with_explicit_pk", a);
 }