Add default scan excluded files settings

crates/project/src/project_settings.rs

@@ -12,7 +12,7 @@ pub struct ProjectSettings {
     pub git: GitSettings,
     // TODO kb better names and docs and tests
     #[serde(default)]
-    pub scan_exclude_files: Vec<String>,
+    pub scan_exclude_files: Option<Vec<String>>,
 }
 
 #[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]

crates/project/src/worktree.rs

@@ -650,7 +650,7 @@ fn start_background_scan_tasks(
 }
 
 fn scan_exclude_files(project_settings: &ProjectSettings) -> Vec<PathMatcher> {
-    project_settings.scan_exclude_files.iter()
+    project_settings.scan_exclude_files.as_deref().unwrap_or(&[]).iter()
     .sorted()
     .filter_map(|pattern| {
         PathMatcher::new(pattern)

crates/project/src/worktree_tests.rs

@@ -910,7 +910,7 @@ async fn test_ignore_inclusions_and_exclusions(cx: &mut TestAppContext) {
         cx.update_global::<SettingsStore, _, _>(|store, cx| {
             store.update_user_settings::<ProjectSettings>(cx, |project_settings| {
                 project_settings.scan_exclude_files =
-                    vec!["**/foo/**".to_string(), "**/.DS_Store".to_string()];
+                    Some(vec!["**/foo/**".to_string(), "**/.DS_Store".to_string()]);
             });
         });
     });