Sonar: explicit imports, fn paths for closures, extract helpers for cognitive complexity

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/core/src/addr.rs

@@ -246,7 +246,7 @@ fn is_r1c1_token(name: &str) -> bool {
         if chars.peek().is_some_and(|c| c.to_ascii_lowercase() == letter) {
             chars.next();
             letters += 1;
-            while chars.peek().is_some_and(|c| c.is_ascii_digit()) {
+            while chars.peek().is_some_and(char::is_ascii_digit) {
                 chars.next();
             }
         }

crates/core/src/value.rs

@@ -245,7 +245,7 @@ impl Value {
             Value::Bool(b) => Ok(if *b { "TRUE".into() } else { "FALSE".into() }),
             Value::Text(t) => Ok(t.to_string()),
             Value::Error(e) => Err(*e),
-            Value::Array(a) => a.data.first().map(|v| v.to_text()).unwrap_or(Ok(String::new())),
+            Value::Array(a) => a.data.first().map(Value::to_text).unwrap_or(Ok(String::new())),
         }
     }
     /// Coercion to a boolean as `IF` does it.
@@ -264,7 +264,7 @@ impl Value {
                 }
             }
             Value::Error(e) => Err(*e),
-            Value::Array(a) => a.data.first().map(|v| v.to_bool()).unwrap_or(Ok(false)),
+            Value::Array(a) => a.data.first().map(Value::to_bool).unwrap_or(Ok(false)),
         }
     }
     /// Display text with General formatting (for logs, CSV and tests).