agent: Improve terminal tool card design (#29712)

To-dos:

- [x] Expose the command to defend against cases where that's just super
long
- [x] Tackle the vertical scroll conflict with panel scroll
- [x] Reduce default font-size

Release Notes:

- N/A

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Agus Zubiaga <hi@aguz.me>

crates/terminal/src/terminal.rs

@@ -601,6 +601,8 @@ pub struct TerminalContent {
     pub cursor_char: char,
     pub terminal_bounds: TerminalBounds,
     pub last_hovered_word: Option<HoveredWord>,
+    pub scrolled_to_top: bool,
+    pub scrolled_to_bottom: bool,
 }
 
 #[derive(Clone)]
@@ -625,6 +627,8 @@ impl Default for TerminalContent {
             cursor_char: Default::default(),
             terminal_bounds: Default::default(),
             last_hovered_word: None,
+            scrolled_to_top: false,
+            scrolled_to_bottom: false,
         }
     }
 }
@@ -1208,6 +1212,14 @@ impl Terminal {
             .push_back(InternalEvent::Scroll(AlacScroll::Bottom));
     }
 
+    pub fn scrolled_to_top(&self) -> bool {
+        self.last_content.scrolled_to_top
+    }
+
+    pub fn scrolled_to_bottom(&self) -> bool {
+        self.last_content.scrolled_to_bottom
+    }
+
     ///Resize the terminal and the PTY.
     pub fn set_size(&mut self, new_bounds: TerminalBounds) {
         if self.last_content.terminal_bounds != new_bounds {
@@ -1405,6 +1417,8 @@ impl Terminal {
             cursor_char: term.grid()[content.cursor.point].c,
             terminal_bounds: last_content.terminal_bounds,
             last_hovered_word: last_content.last_hovered_word.clone(),
+            scrolled_to_top: content.display_offset == term.history_size(),
+            scrolled_to_bottom: content.display_offset == 0,
         }
     }