Settings refactor (#38367)

Co-Authored-By: Ben K <ben@zed.dev>
Co-Authored-By: Anthony <anthony@zed.dev>
Co-Authored-By: Mikayla <mikayla@zed.dev>

Release Notes:

- settings: Major internal changes to settings. The primary user-facing
effect is that some settings which did not make sense in project
settings files are no-longer read from there. (For example the inline
blame settings)

---------

Co-authored-by: Ben Kunkle <ben@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Anthony <anthony@zed.dev>

crates/google_ai/src/google_ai.rs

@@ -4,6 +4,7 @@ use anyhow::{Result, anyhow, bail};
 use futures::{AsyncBufReadExt, AsyncReadExt, StreamExt, io::BufReader, stream::BoxStream};
 use http_client::{AsyncBody, HttpClient, Method, Request as HttpRequest};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
+pub use settings::ModelMode as GoogleModelMode;
 
 pub const API_URL: &str = "https://generativelanguage.googleapis.com";
 
@@ -295,16 +296,6 @@ pub struct ThinkingConfig {
     pub thinking_budget: u32,
 }
 
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
-#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq)]
-pub enum GoogleModelMode {
-    #[default]
-    Default,
-    Thinking {
-        budget_tokens: Option<u32>,
-    },
-}
-
 #[derive(Debug, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct GenerationConfig {