documentation & guidance updates, getting things done, fixing a possible NDE if you change env vars, changes to enable user picking "done", minor test changes, minor goal selection prompt improvements

models/data_types.py

@@ -42,3 +42,8 @@ class ValidationResult:
         # Initialize empty dict if None
         if self.validationFailedReason is None:
             self.validationFailedReason = {}
+
+@dataclass
+class EnvLookupInput:
+    env_var_name: str
+    default: bool