Uploaded campaign_controller

app/controller/campaign_controller.py

@@ -0,0 +1,13 @@
+def on_campaign_select(dfs, campaign_name):
+    """
+    dfs = full dataset
+    """
+
+    df = dfs["campaigns"].copy()
+    filtered = df[df["name"] == campaign_name]
+
+    return {
+        "campaign_name": campaign_name,
+        "campaign_df": filtered,
+        "full_dfs": dfs   # IMPORTANT: keep full dataset for analytics
+    }