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.

src/dsl/walker/highlight.rs

@@ -24,8 +24,8 @@
 use crate::dsl::grammar::HighlightClass;
 use crate::dsl::walker::context::WalkContext;
 use crate::dsl::walker::lex_helpers::{
-    consume_bare_path, consume_flag, consume_ident, consume_number_literal,
-    consume_string_literal, skip_whitespace,
+    consume_bare_path, consume_flag, consume_ident, consume_number_literal, consume_string_literal,
+    skip_whitespace,
 };
 use crate::dsl::walker::outcome::{ByteClass, WalkBound};
 
@@ -47,16 +47,11 @@ pub fn highlight_runs(source: &str) -> Vec<ByteClass> {
 /// token, producing the keyword classes the renderer needs to
 /// colour `select` / `from` / `where` / `union` / `case` / etc.
 #[must_use]
-pub fn highlight_runs_in_mode(
-    source: &str,
-    mode: crate::mode::Mode,
-) -> Vec<ByteClass> {
+pub fn highlight_runs_in_mode(source: &str, mode: crate::mode::Mode) -> Vec<ByteClass> {
     let mut ctx = WalkContext::new();
     ctx.mode = mode;
     let (result, _cmd) = super::walk(source, WalkBound::EndOfInput, &mut ctx);
-    let mut classes: Vec<ByteClass> = result
-        .map(|r| r.per_byte_class)
-        .unwrap_or_default();
+    let mut classes: Vec<ByteClass> = result.map(|r| r.per_byte_class).unwrap_or_default();
 
     let scan_start = classes.last().map_or(0, |c| c.end);
     scan_remainder(source, scan_start, &mut classes);
@@ -133,9 +128,7 @@ fn scan_remainder(source: &str, start: usize, classes: &mut Vec<ByteClass>) {
                     .get(pos + 1)
                     .copied()
                     .is_some_and(|c| c.is_ascii_digit()));
-        if looks_like_number
-            && let Some((s, e)) = consume_number_literal(source, pos)
-        {
+        if looks_like_number && let Some((s, e)) = consume_number_literal(source, pos) {
             classes.push(ByteClass {
                 start: s,
                 end: e,
@@ -222,8 +215,14 @@ mod tests {
             "no Error highlight on a valid m:n line: {runs:?}"
         );
         let kinds: Vec<HighlightClass> = runs.iter().map(|(_, _, c)| *c).collect();
-        assert!(kinds.contains(&HighlightClass::Keyword), "keywords highlighted: {runs:?}");
-        assert!(kinds.contains(&HighlightClass::Identifier), "table names highlighted: {runs:?}");
+        assert!(
+            kinds.contains(&HighlightClass::Keyword),
+            "keywords highlighted: {runs:?}"
+        );
+        assert!(
+            kinds.contains(&HighlightClass::Identifier),
+            "table names highlighted: {runs:?}"
+        );
     }
 
     #[test]
@@ -276,10 +275,7 @@ mod tests {
     #[test]
     fn flag_classified_via_fallback() {
         // Walker doesn't engage for a bare `--all-rows`.
-        assert_eq!(
-            run("--all-rows"),
-            vec![(0, 10, HighlightClass::Flag)],
-        );
+        assert_eq!(run("--all-rows"), vec![(0, 10, HighlightClass::Flag)],);
     }
 
     #[test]
@@ -445,15 +441,13 @@ mod tests {
         // dispatcher, so only the entry word would highlight).
         let runs = run_advanced("select * from t");
         assert!(
-            runs.iter().any(|(s, e, c)| {
-                *c == HighlightClass::Keyword && (*s, *e) == (0, 6)
-            }),
+            runs.iter()
+                .any(|(s, e, c)| { *c == HighlightClass::Keyword && (*s, *e) == (0, 6) }),
             "expected `select` keyword span 0..6; got {runs:?}",
         );
         assert!(
-            runs.iter().any(|(s, e, c)| {
-                *c == HighlightClass::Keyword && (*s, *e) == (9, 13)
-            }),
+            runs.iter()
+                .any(|(s, e, c)| { *c == HighlightClass::Keyword && (*s, *e) == (9, 13) }),
             "expected `from` keyword span 9..13; got {runs:?}",
         );
     }
@@ -514,18 +508,37 @@ mod tests {
         let insert = keywords_of(
             "insert into t (a) values (1) on conflict (a) do update set a = excluded.a returning a",
         );
-        for kw in ["insert", "into", "values", "on", "conflict", "do", "update", "set", "returning"] {
-            assert!(insert.contains(&kw), "INSERT/UPSERT: missing `{kw}`; got {insert:?}");
+        for kw in [
+            "insert",
+            "into",
+            "values",
+            "on",
+            "conflict",
+            "do",
+            "update",
+            "set",
+            "returning",
+        ] {
+            assert!(
+                insert.contains(&kw),
+                "INSERT/UPSERT: missing `{kw}`; got {insert:?}"
+            );
         }
 
         let update = keywords_of("update t set a = 1 where id = 2 returning a");
         for kw in ["update", "set", "where", "returning"] {
-            assert!(update.contains(&kw), "UPDATE: missing `{kw}`; got {update:?}");
+            assert!(
+                update.contains(&kw),
+                "UPDATE: missing `{kw}`; got {update:?}"
+            );
         }
 
         let delete = keywords_of("delete from t where id = 1 returning *");
         for kw in ["delete", "from", "where", "returning"] {
-            assert!(delete.contains(&kw), "DELETE: missing `{kw}`; got {delete:?}");
+            assert!(
+                delete.contains(&kw),
+                "DELETE: missing `{kw}`; got {delete:?}"
+            );
         }
     }
 }