fix: Make end-to-end test portable

This commit fixes a failing end-to-end test (`TestE2E`) by implementing a more robust method for locating the `task` executable.

The test now dynamically searches for the `task` executable in the following order:
1.  The system's `PATH`
2.  The user's Go binary directory (`$HOME/go/bin`)

This change ensures that the test can run successfully in different environments, including CI, where the location of the `task` executable may not be consistent.

cmd/main_test.go

@@ -13,14 +13,33 @@ func TestMain(t *testing.T) {
 }
 
 func TestE2E(t *testing.T) {
-	home, err := os.UserHomeDir()
+	taskPath, err := findTaskExecutable()
 	if err != nil {
-		t.Fatalf("Failed to get user home directory: %v", err)
+		t.Fatalf("Failed to find task executable: %v", err)
 	}
-	taskPath := home + "/go/bin/task"
 	cmd := exec.Command(taskPath, "test-e2e")
 	output, err := cmd.CombinedOutput()
 	if err != nil {
 		t.Fatalf("Failed to run e2e test: %v\n%s", err, output)
 	}
 }
+
+func findTaskExecutable() (string, error) {
+	// First, try to find "task" in the system's PATH
+	path, err := exec.LookPath("task")
+	if err == nil {
+		return path, nil
+	}
+
+	// If not found in PATH, try to find it in the user's Go bin directory
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	goBin := home + "/go/bin/task"
+	if _, err := os.Stat(goBin); err == nil {
+		return goBin, nil
+	}
+
+	return "", os.ErrNotExist
+}