refactor: extend ScenarioBase with weather, max_frames, and ego_spawn_point props

- Added ego_spawn_point for deterministic scenario starts
- Implemented apply_parameters() for CLI parameter injection
- Moved weather mapping logic to centralized src/utils.py
- Emptied scenarios/__init__.py to prevent side-effect imports during discovery

scenarios/__init__.py

@@ -1,2 +1,2 @@
 # scenarios package
-from .showcase import ShowcaseScenario
+# This file is intentionally empty to avoid side-effects when discovering modules.

scenarios/base.py

@@ -12,6 +12,8 @@ Every scenario must subclass ScenarioBase and implement:
 Optional overrides:
     - on_ego_spawned()
     - get_scenario_metadata()
+    - weather (property)
+    - max_frames (property)
 """
 
 from abc import ABC, abstractmethod
@@ -85,9 +87,36 @@ class ScenarioBase(ABC):
         """
 
     # ------------------------------------------------------------------
-    # Optional hooks (default no-ops — override as needed)
+    # Optional hooks & Properties (default no-ops — override as needed)
     # ------------------------------------------------------------------
 
+    @property
+    def weather(self) -> str:
+        """
+        Override to request a specific weather preset for this scenario.
+        If None, the global config or CLI default will be used.
+        """
+        return None
+
+    @property
+    def max_frames(self) -> int:
+        """
+        Override to request a specific duration for this scenario.
+        If None, the global config or CLI default will be used.
+        """
+        return None
+
+    @property
+    def ego_spawn_point(self):
+        """
+        Override to request a specific spawn point for the ego vehicle.
+        Returns:
+          - int: index in the world's spawn points list.
+          - carla.Transform: absolute spawn position and rotation.
+        If None, the global config or CLI default index will be used.
+        """
+        return None
+
     def on_ego_spawned(self, ego_vehicle) -> None:
         """
         Called immediately after the ego vehicle is spawned.
@@ -104,6 +133,28 @@ class ScenarioBase(ABC):
         """
         return {"scenario": self.name}
 
+    def apply_parameters(self, params: dict) -> None:
+        """
+        Allow the orchestrator to inject parameters parsed from CLI.
+        This maps keys in `params` to existing attributes on the scenario.
+        Useful for non-code tuning.
+        """
+        for key, value in params.items():
+            if hasattr(self, key):
+                # Try to preserve type
+                existing_val = getattr(self, key)
+                try:
+                    if isinstance(existing_val, bool):
+                        typed_val = str(value).lower() in ("true", "1", "yes")
+                    else:
+                        typed_val = type(existing_val)(value)
+                    setattr(self, key, typed_val)
+                    print(f"[Scenario] Injected param: {key} = {typed_val}")
+                except Exception as e:
+                    print(f"[WARN] Failed to inject param '{key}={value}': {e}")
+            else:
+                print(f"[WARN] Scenario '{self.name}' has no attribute '{key}'")
+
     # ------------------------------------------------------------------
     # Shared helpers for subclasses
     # ------------------------------------------------------------------

src/utils.py

@@ -0,0 +1,29 @@
+import carla
+
+def get_weather_preset(name: str):
+    """
+    Map names (case-insensitive, partial matching) to carla.WeatherParameters.
+    """
+    weather_presets = {
+        "Clear": carla.WeatherParameters.ClearNoon,
+        "Cloudy": carla.WeatherParameters.CloudyNoon,
+        "Wet": carla.WeatherParameters.WetNoon,
+        "SoftRain": carla.WeatherParameters.SoftRainNoon,
+        "Rain": carla.WeatherParameters.HardRainNoon,
+        "Sunset": carla.WeatherParameters.ClearSunset,
+        "Night": carla.WeatherParameters(
+            sun_altitude_angle=-90.0,
+            cloudiness=0.0,
+            precipitation=10.0,
+            precipitation_deposits=10.0,
+            wind_intensity=0.0,
+            fog_density=0.0,
+            fog_distance=0.0,
+            wetness=0.0
+        )
+    }
+    
+    for k, v in weather_presets.items():
+        if k.lower() in name.lower():
+            return v
+    return carla.WeatherParameters.ClearNoon