Fix Apps Script integration with main server

- Add appscript to --tools CLI choices, tool_imports, and tool_icons
- Add script service to SERVICE_CONFIGS in service_decorator
- Add script scope imports and SCOPE_GROUPS mappings
- Fix variable shadowing in _get_script_project_impl

These changes complete the Apps Script integration by adding the
missing wiring in main.py and service_decorator.py that was needed
to make the feature functional.

main.py

@@ -104,6 +104,7 @@ def main():
             "slides",
             "tasks",
             "search",
+            "appscript",
         ],
         help="Specify which tools to register. If not provided, all tools are registered.",
     )
@@ -184,6 +185,7 @@ def main():
         "slides": lambda: import_module("gslides.slides_tools"),
         "tasks": lambda: import_module("gtasks.tasks_tools"),
         "search": lambda: import_module("gsearch.search_tools"),
+        "appscript": lambda: import_module("gappsscript.apps_script_tools"),
     }
 
     tool_icons = {
@@ -197,6 +199,7 @@ def main():
         "slides": "🖼️",
         "tasks": "✓",
         "search": "🔍",
+        "appscript": "📜",
     }
 
     # Determine which tools to import based on arguments