Rename assistant_settings to agent_settings (#31513)

This PR renames the `assistant_settings` crate to `agent_settings`, as
well a number of constructs within it.

Release Notes:

- N/A

crates/agent/src/terminal_inline_assistant.rs

@@ -5,8 +5,8 @@ use crate::inline_prompt_editor::{
 };
 use crate::terminal_codegen::{CLEAR_INPUT, CodegenEvent, TerminalCodegen};
 use crate::thread_store::{TextThreadStore, ThreadStore};
+use agent_settings::AgentSettings;
 use anyhow::{Context as _, Result};
-use assistant_settings::AssistantSettings;
 use client::telemetry::Telemetry;
 use collections::{HashMap, VecDeque};
 use editor::{MultiBuffer, actions::SelectAll};
@@ -271,7 +271,7 @@ impl TerminalInlineAssistant {
             .inline_assistant_model()
             .context("No inline assistant model")?;
 
-        let temperature = AssistantSettings::temperature_for_model(&model, cx);
+        let temperature = AgentSettings::temperature_for_model(&model, cx);
 
         Ok(cx.background_spawn(async move {
             let mut request_message = LanguageModelRequestMessage {