Enhance TUI and core functionality: add header rendering, improve message formatting, and refine provider/model handling logic. Update dependencies.

crates/owlen-core/src/formatting.rs

@@ -15,7 +15,7 @@ impl MessageFormatter {
         Self {
             wrap_width: wrap_width.max(20),
             show_role_labels,
-            preserve_empty_lines: true,
+            preserve_empty_lines: false,
         }
     }
 
@@ -25,36 +25,51 @@ impl MessageFormatter {
         self
     }
 
-    /// Render a message to a list of visual lines ready for display
-    pub fn format_message(&self, message: &Message) -> Vec<String> {
-        let mut lines = Vec::new();
+    /// Update the wrap width
+    pub fn set_wrap_width(&mut self, width: usize) {
+        self.wrap_width = width.max(20);
+    }
+
+    pub fn format_message(&self, message: &Message) -> Vec<String> {
+        // 1) Normalize line breaks to '\n' (handles CR, NEL, LS, PS)
+        let normalized: String = message
+            .content
+            .chars()
+            .map(|ch| match ch {
+                '\r' | '\u{0085}' | '\u{2028}' | '\u{2029}' => '\n',
+                _ => ch,
+            })
+            .collect();
+
+        // 2) Collapse: remove whitespace-only lines; keep exactly one '\n' between content lines
+        let mut content = normalized
+            .split('\n')
+            .map(|l| l.trim_end())               // trim trailing spaces per line
+            .filter(|l| !l.trim().is_empty())    // drop blank/whitespace-only lines
+            .collect::<Vec<_>>()
+            .join("\n")
+            .trim()                               // trim leading/trailing whitespace
+            .to_string();
 
-        let mut content = message.content.trim_end().to_string();
         if content.is_empty() && self.preserve_empty_lines {
             content.push(' ');
         }
 
+        // 3) Wrap
         let options = Options::new(self.wrap_width)
             .break_words(true)
             .word_separator(textwrap::WordSeparator::UnicodeBreakProperties);
 
-        let wrapped = wrap(&content, &options);
+        // 4) Post: rtrim each visual line; drop any whitespace-only lines
+        let mut lines: Vec<String> = wrap(&content, &options)
+            .into_iter()
+            .map(|s| s.trim_end().to_string())
+            .filter(|s| !s.trim().is_empty())
+            .collect();
 
-        if self.show_role_labels {
-            let label = format!("{}:", message.role.to_string().to_uppercase());
-            if let Some(first) = wrapped.first() {
-                lines.push(format!("{label} {first}"));
-                for line in wrapped.iter().skip(1) {
-                    lines.push(format!("{:width$} {line}", "", width = label.len()));
-                }
-            } else {
-                lines.push(label);
-            }
-        } else {
-            for line in wrapped {
-                lines.push(line.into_owned());
-            }
-        }
+        // 5) Belt & suspenders: remove leading/trailing blanks if any survived
+        while lines.first().map_or(false, |s| s.trim().is_empty()) { lines.remove(0); }
+        while lines.last().map_or(false,  |s| s.trim().is_empty()) { lines.pop(); }
 
         lines
     }

crates/owlen-core/src/session.rs

@@ -87,6 +87,11 @@ impl SessionController {
         &self.formatter
     }
 
+    /// Update the wrap width of the message formatter
+    pub fn set_formatter_wrap_width(&mut self, width: usize) {
+        self.formatter.set_wrap_width(width);
+    }
+
     /// Access configuration
     pub fn config(&self) -> &Config {
         &self.config