fix(fonts): recognize URW -Medi suffix as bold

URW Type 1 fonts abbreviate the Medium weight as "Medi" in the font
name (NimbusRomNo9L-Medi is the Times-Bold substitute embedded by most
LaTeX toolchains; -MediItal is bold italic). is_bold_font only matched
the full word "medium", so bold ran undetected across LaTeX-produced
PDFs — dropping ** emphasis and starving bold-based heading detection
of its signal.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/text_utils.rs

@@ -93,6 +93,9 @@ pub fn is_bold_font(font_name: &str) -> bool {
         || lower.contains("extrabold")
         || lower.contains("ultrabold")
         || lower.contains("medium") && !lower.contains("mediumitalic") // Some fonts use Medium for semi-bold
+        // URW Type 1 fonts abbreviate Medium as "Medi" (e.g. NimbusRomNo9L-Medi,
+        // the Times-Bold substitute in LaTeX documents; -MediItal is bold italic).
+        || lower.contains("-medi") && !lower.contains("mediumital")
 }
 
 /// Detect if a font name indicates italic/oblique style
@@ -762,6 +765,17 @@ mod tests {
     use super::*;
     use crate::types::ItemType;
 
+    #[test]
+    fn bold_font_urw_medi_abbreviation() {
+        // URW Type 1 fonts (LaTeX default Times) abbreviate Medium as "Medi"
+        assert!(is_bold_font("NROFIU+NimbusRomNo9L-Medi"));
+        assert!(is_bold_font("NimbusRomNo9L-MediItal"));
+        assert!(!is_bold_font("DSSZWN+NimbusRomNo9L-Regu"));
+        assert!(!is_bold_font("NimbusRomNo9L-ReguItal"));
+        // Medium-Italic exclusion still holds
+        assert!(!is_bold_font("Foo-MediumItalic"));
+    }
+
     #[test]
     fn strip_soft_hyphen() {
         assert_eq!(expand_ligatures("con\u{00AD}tent"), "content");