refactor(markdown-parser): replace remaining magic numbers with named constants (#9264)

Author: jfmcdowell

crates/biome_markdown_parser/src/parser.rs

@@ -470,7 +470,7 @@ fn count_leading_indent(text: &str) -> usize {
     for c in text.chars() {
         match c {
             ' ' => count += 1,
-            '\t' => count += 4,
+            '\t' => count += TAB_STOP_SPACES,
             _ => break,
         }
     }

crates/biome_markdown_parser/src/syntax/mod.rs

@@ -534,7 +534,7 @@ fn consume_indent_prefix(p: &mut MarkdownParser, indent: usize) {
         if text == " " {
             consumed += 1;
         } else if text == "\t" {
-            consumed += 4;
+            consumed += TAB_STOP_SPACES;
         } else {
             break;
         }

crates/biome_markdown_parser/src/to_html.rs

@@ -1148,7 +1148,9 @@ fn render_fenced_code_block(
         indent
     });
     let container_indent = list_indent + quote_indent;
-    let fence_indent = fence_leading_indent.saturating_sub(container_indent).min(3);
+    let fence_indent = fence_leading_indent
+        .saturating_sub(container_indent)
+        .min(MAX_BLOCK_PREFIX_INDENT);
     let content_indent = container_indent + fence_indent;
 
     // Get info string (language) - process escapes