fix(cli): flex-col min-width clamping and formatting consistency

- render.rs: clamp flex column width to min(min_flex, natural) instead
  of a hardcoded 20, preventing layout overflow when natural width is
  small; rewrites flex_width test to be terminal-independent
- list/issues.rs: adopt .flex_col() builder on table construction
- list/mrs.rs, list/notes.rs: consolidate multi-line StyledCell::styled
  calls to single-line format
- explain.rs: adopt flex_width() for related-issue title truncation,
  consolidate multi-line formatting

src/cli/commands/explain.rs

@@ -1137,7 +1137,11 @@ pub fn print_explain(result: &ExplainResult) {
 
     // Entity header
     let (type_label, ref_style, ref_str) = match result.entity.entity_type.as_str() {
-        "issue" => ("Issue", Theme::issue_ref(), format!("#{}", result.entity.iid)),
+        "issue" => (
+            "Issue",
+            Theme::issue_ref(),
+            format!("#{}", result.entity.iid),
+        ),
         "merge_request" => ("MR", Theme::mr_ref(), format!("!{}", result.entity.iid)),
         _ => (
             result.entity.entity_type.as_str(),
@@ -1246,8 +1250,10 @@ pub fn print_explain(result: &ExplainResult) {
             println!(
                 "    {} by {} ({} notes, last: {})",
                 Theme::dim().render(&t.discussion_id),
-                Theme::username()
-                    .render(&format!("@{}", t.started_by.as_deref().unwrap_or("unknown"))),
+                Theme::username().render(&format!(
+                    "@{}",
+                    t.started_by.as_deref().unwrap_or("unknown")
+                )),
                 t.note_count,
                 Theme::dim().render(&to_relative(&t.last_note_at))
             );
@@ -1300,7 +1306,10 @@ pub fn print_explain(result: &ExplainResult) {
             println!(
                 "    {arrow} {} {}{state_str} ({})",
                 ref_style.render(&format!("{ref_prefix}{}", ri.iid)),
-                render::truncate(ri.title.as_deref().unwrap_or("(untitled)"), render::flex_width(30, 20)),
+                render::truncate(
+                    ri.title.as_deref().unwrap_or("(untitled)"),
+                    render::flex_width(30, 20)
+                ),
                 Theme::dim().render(&ri.reference_type)
             );
         }