fix inpout scroll issues (#14597)

## Description
<!-- Please remember to add your design buddy onto the PR for review, if
it contains any UI changes! -->

Input scrolling was messed up because our calculation for the size of
the input was wrong. This fixes that.

## Testing
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- [x] I have manually tested my changes locally with `./script/run`

## Agent Mode
- [x] Warp Agent Mode - This PR was created via Warp's AI Agent Mode

Author: harryalbert

crates/warp_tui/src/terminal_session_view.rs

@@ -169,6 +169,8 @@ const INITIAL_INPUT_WIDTH: u16 = 80;
 const INLINE_MENU_TOP_PADDING_ROWS: u16 = 1;
 const MAX_READ_ONLY_MENU_ROWS: u16 = 10;
 const MAX_INPUT_TEXT_ROWS: u16 = 6;
+/// Top and bottom border rows plus one padding row inside each border.
+const BORDERED_INPUT_CHROME_ROWS: u16 = 4;
 const AUTO_APPROVE_FEEDBACK_DURATION: Duration = Duration::from_secs(3);
 const VOICE_INPUT_BORDER_REPAINT_INTERVAL: Duration = Duration::from_millis(33);
 
@@ -2649,7 +2651,7 @@ impl TuiTerminalSessionView {
         }
         content = content.child(
             TuiConstrainedBox::new(input)
-                .with_max_rows(MAX_INPUT_TEXT_ROWS + 2)
+                .with_max_rows(MAX_INPUT_TEXT_ROWS + BORDERED_INPUT_CHROME_ROWS)
                 .finish(),
         );
         let footer = if let Some(footer) = self.api_keys_menu.as_ref(ctx).footer(ctx) {

crates/warp_tui/src/terminal_session_view_tests.rs

@@ -1376,6 +1376,26 @@ fn render_footer_lines(
 ) -> Vec<String> {
     render_footer(app, view, width).to_lines()
 }
+#[test]
+fn input_area_renders_all_six_editor_rows() {
+    App::test((), |mut app| async move {
+        let fixture = focus_test_fixture(&mut app);
+        let (view, _) = add_focus_test_session(&mut app, &fixture, true);
+        view.update(&mut app, |view, ctx| {
+            view.input_view.update(ctx, |input, ctx| {
+                input.set_text("input-0\ninput-1\ninput-2\ninput-3\ninput-4\ninput-5", ctx);
+            });
+        });
+
+        let rendered = render_session(&mut app, &view, 80, 24).join("\n");
+        for row in 0..6 {
+            assert!(
+                rendered.contains(&format!("input-{row}")),
+                "input row {row} should be visible:\n{rendered}"
+            );
+        }
+    });
+}
 
 /// Dispatches `event` into the retained session element tree with the session
 /// view as the action origin, returning whether the tree handled it.