Refactor file handling for custom_sdkconfig

Author: Jason2866

builder/frameworks/espidf.py

@@ -213,8 +213,8 @@ def load_custom_sdkconfig_file():
                         print(f"Error decoding response from {file_entry}: {e}")
                         return ""
 
-            # Handle local files
-            if "file://" in file_entry:
+            # Treat as local file if explicitly file:// or a non-URL token that isn't a flag
+            if "file://" in file_entry or ("://" not in file_entry and "=" not in file_entry):
                 file_ref = file_entry[7:] if file_entry.startswith("file://") else file_entry
 
                 if os.path.isabs(file_ref):
@@ -561,7 +561,7 @@ def populate_idf_env_vars(idf_env):
         os.path.dirname(get_python_exe()),
     ]
 
-    idf_env["PATH"] = os.pathsep.join(additional_packages + [idf_env["PATH"]])
+    idf_env["PATH"] = os.pathsep.join([*additional_packages, idf_env["PATH"]])
     idf_env["ESP_ROM_ELF_DIR"] = platform.get_package_dir("tool-esp-rom-elfs")