Keep runtime files inside application support

src/app.rs

@@ -2453,7 +2453,7 @@ fn export_markdown(title: &str, conversation: &[ChatMessage]) -> String {
     output
 }
 
-fn application_support_path() -> PathBuf {
+pub(crate) fn application_support_path() -> PathBuf {
     std::env::var_os("HOME")
         .map(PathBuf::from)
         .unwrap_or_else(|| PathBuf::from("."))
@@ -2462,10 +2462,14 @@ fn application_support_path() -> PathBuf {
         .join(APP_ID)
 }
 
-fn models_path() -> PathBuf {
+pub(crate) fn models_path() -> PathBuf {
     application_support_path().join("models")
 }
 
+pub(crate) fn browser_profile_path() -> PathBuf {
+    application_support_path().join("browser")
+}
+
 /// The settings file, beside the project database.
 pub(crate) fn config_path() -> PathBuf {
     application_support_path().join("config.yaml")
@@ -2911,4 +2915,36 @@ mod tests {
         );
         assert!(!exported.contains("private"));
     }
+
+    #[test]
+    fn owned_runtime_paths_stay_in_application_support() {
+        let root = application_support_path();
+        assert!(models_path().starts_with(&root));
+        assert!(browser_profile_path().starts_with(&root));
+        assert!(config_path().starts_with(&root));
+        assert!(kv_cache_path().starts_with(&root));
+    }
+
+    #[test]
+    fn source_does_not_depend_on_a_sibling_ds4_checkout() {
+        fn scan(path: &Path, forbidden: &str) {
+            if path.is_dir() {
+                for entry in fs::read_dir(path).unwrap() {
+                    scan(&entry.unwrap().path(), forbidden);
+                }
+            } else if let Ok(source) = fs::read_to_string(path) {
+                assert!(
+                    !source.contains(forbidden),
+                    "{} references a sibling DS4 checkout",
+                    path.display()
+                );
+            }
+        }
+
+        let root = Path::new(env!("CARGO_MANIFEST_DIR"));
+        let forbidden = format!("{}/", ["..", "ds4"].join("/"));
+        for path in ["src", "native", "build.rs", "Cargo.toml", "Makefile"] {
+            scan(&root.join(path), &forbidden);
+        }
+    }
 }