Overhaul inline assistant (#12846)

This pull request introduces a new diff mechanism that helps users
understand exactly which lines were changed by the LLM.

Release Notes:

- N/A

crates/ui/src/components/icon.rs

@@ -106,6 +106,7 @@ pub enum IconName {
     Code,
     Collab,
     Command,
+    Context,
     Control,
     Copilot,
     CopilotDisabled,
@@ -170,6 +171,7 @@ pub enum IconName {
     Rerun,
     Return,
     Reveal,
+    RotateCw,
     Save,
     Screen,
     SelectAll,
@@ -186,6 +188,7 @@ pub enum IconName {
     Split,
     Star,
     StarFilled,
+    Stop,
     Strikethrough,
     Supermaven,
     SupermavenDisabled,
@@ -233,6 +236,7 @@ impl IconName {
             IconName::Code => "icons/code.svg",
             IconName::Collab => "icons/user_group_16.svg",
             IconName::Command => "icons/command.svg",
+            IconName::Context => "icons/context.svg",
             IconName::Control => "icons/control.svg",
             IconName::Copilot => "icons/copilot.svg",
             IconName::CopilotDisabled => "icons/copilot_disabled.svg",
@@ -297,6 +301,7 @@ impl IconName {
             IconName::ReplyArrowRight => "icons/reply_arrow_right.svg",
             IconName::Rerun => "icons/rerun.svg",
             IconName::Return => "icons/return.svg",
+            IconName::RotateCw => "icons/rotate_cw.svg",
             IconName::Save => "icons/save.svg",
             IconName::Screen => "icons/desktop.svg",
             IconName::SelectAll => "icons/select_all.svg",
@@ -313,6 +318,7 @@ impl IconName {
             IconName::Split => "icons/split.svg",
             IconName::Star => "icons/star.svg",
             IconName::StarFilled => "icons/star_filled.svg",
+            IconName::Stop => "icons/stop.svg",
             IconName::Strikethrough => "icons/strikethrough.svg",
             IconName::Supermaven => "icons/supermaven.svg",
             IconName::SupermavenDisabled => "icons/supermaven_disabled.svg",