feat: add setup notebook and update env example for Athena

studies/202602_AmazonConnect/config.py

@@ -31,9 +31,14 @@ DISCOUNT_RATE = 0.10
 #: Analysis horizon (years).
 ANALYSIS_YEARS = 3
 
-#: Optional Athena Proposal ID this tool is linked to (when known).
-PROPOSAL_ID: int | None = (
-    int(os.environ["PALLADIUM_PROPOSAL_ID"])
-    if os.getenv("PALLADIUM_PROPOSAL_ID")
-    else None
-)
+def _int_env(name: str) -> int | None:
+    raw = os.getenv(name, "").strip()
+    return int(raw) if raw else None
+
+
+#: Athena Proposal PK this tool is linked to (a TEI tool must attach to a
+#: Proposal OR an Engagement — set exactly one).
+PROPOSAL_ID: int | None = _int_env("PALLADIUM_PROPOSAL_ID")
+
+#: Athena Engagement PK (alternative attachment point).
+ENGAGEMENT_ID: int | None = _int_env("PALLADIUM_ENGAGEMENT_ID")