editor: Add support for no scroll margin in full mode (#41838)

Noticed this whilst testing the Docker debugger. I randomly scrolled the
console off screen and was confused briefly as to why this was the case.

Release Notes:

- The debugger query console will no longer needlessly overscroll.

crates/agent_ui/src/acp/entry_view_state.rs

@@ -4,7 +4,7 @@ use acp_thread::{AcpThread, AgentThreadEntry};
 use agent::HistoryStore;
 use agent_client_protocol::{self as acp, ToolCallId};
 use collections::HashMap;
-use editor::{Editor, EditorMode, MinimapVisibility};
+use editor::{Editor, EditorMode, MinimapVisibility, SizingBehavior};
 use gpui::{
     AnyEntity, App, AppContext as _, Entity, EntityId, EventEmitter, FocusHandle, Focusable,
     ScrollHandle, SharedString, TextStyleRefinement, WeakEntity, Window,
@@ -357,7 +357,7 @@ fn create_editor_diff(
             EditorMode::Full {
                 scale_ui_elements_with_buffer_font_size: false,
                 show_active_line_background: false,
-                sized_by_content: true,
+                sizing_behavior: SizingBehavior::SizeByContent,
             },
             diff.read(cx).multibuffer().clone(),
             None,

crates/agent_ui/src/acp/thread_view.rs

@@ -17,7 +17,9 @@ use client::zed_urls;
 use cloud_llm_client::PlanV1;
 use collections::{HashMap, HashSet};
 use editor::scroll::Autoscroll;
-use editor::{Editor, EditorEvent, EditorMode, MultiBuffer, PathKey, SelectionEffects};
+use editor::{
+    Editor, EditorEvent, EditorMode, MultiBuffer, PathKey, SelectionEffects, SizingBehavior,
+};
 use file_icons::FileIcons;
 use fs::Fs;
 use futures::FutureExt as _;
@@ -893,7 +895,7 @@ impl AcpThreadView {
                     EditorMode::Full {
                         scale_ui_elements_with_buffer_font_size: false,
                         show_active_line_background: false,
-                        sized_by_content: false,
+                        sizing_behavior: SizingBehavior::ExcludeOverscrollMargin,
                     },
                     cx,
                 )