fix: handle Option<PathBuf> from resolve_dot_venv correctly

- find.rs: resolve_dot_venv returns Option<PathBuf>, use if-let to
  conditionally insert into search paths vec
- environment_locations.rs: fix bug where ? operator on None would
  short-circuit the function, losing already-collected environments
- path.rs: remove trailing whitespace in doc comments (fmt check)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: edvilme

crates/pet-fs/src/path.rs

@@ -336,9 +336,9 @@ fn get_user_home() -> Option<PathBuf> {
 
 /// Resolves the `.venv` entry in a directory to the virtual environment path. `.venv` may be either
 /// - A **directory**: The virtual environment itself (traditional convention)
-/// - A **file**: A text file containing the path (relative or absolute) to the virtual environment 
+/// - A **file**: A text file containing the path (relative or absolute) to the virtual environment
 ///   located somewhere else in disk (PEP 832 convention)
-/// 
+///
 /// # Resolution order
 /// 1. If `<dir>/.venv` is a directory, return that path.
 /// 2. If `<dir>/.venv` is a file, read its contents, trim whitespaces, and resolve the path:

crates/pet-poetry/src/environment_locations.rs

@@ -109,9 +109,10 @@ fn list_all_environments_from_project_config(
     // Order of preference is Project (local config) > EnvVariable > Global
     if should_use_local_venv_as_poetry_env(global, &local, env) {
         // If virtualenvs are in the project, then look for .venv
-        let venv = resolve_dot_venv(path);
-        if venv.clone()?.is_dir() {
-            envs.push(venv?);
+        if let Some(venv) = resolve_dot_venv(path) {
+            if venv.is_dir() {
+                envs.push(venv);
+            }
         }
     }
     Some(envs)

crates/pet/src/find.rs

@@ -277,12 +277,14 @@ pub fn find_python_environments_in_workspace_folder_recursive(
     let mut paths_to_search_first = vec![
         // Possible this is a virtual env
         workspace_folder.to_path_buf(),
-        // Optimize for finding these first.
-        resolve_dot_venv(workspace_folder),
         workspace_folder.join(".conda"),
         workspace_folder.join(".virtualenv"),
         workspace_folder.join("venv"),
     ];
+    // Optimize for finding .venv first (supports PEP 832 file-based .venv).
+    if let Some(dot_venv) = resolve_dot_venv(workspace_folder) {
+        paths_to_search_first.insert(1, dot_venv);
+    }
 
     // Add all subdirectories of .pixi/envs/**
     if let Ok(reader) = fs::read_dir(workspace_folder.join(".pixi").join("envs")) {