fix base costs and import backstage in ctm notebook

studies/202512_GenesysCX/ctm-token-calculator/tokencalc/appendix4.py

@@ -99,6 +99,19 @@ TCO_VERBATIM: dict[str, float] = {
     "npv_discount_rate": 0.135,    # deck's benefit-NPV rate
 }
 
+#: Actual contracted values where they differ from the deck — 🟢
+#: contractual. Layered over TCO_VERBATIM, which stays the untouched
+#: record of what Genesys pitched (the anchor CTM can follow);
+#: presentation reads through :func:`tco`.
+TCO_CONTRACTED: dict[str, float] = {
+    "ccaas_annual": 3_200_000,     # signed licence run-rate (deck pitched $4.3M/yr)
+}
+
+
+def tco(key: str) -> float:
+    """Contracted value where one exists, else the deck's verbatim anchor."""
+    return TCO_CONTRACTED.get(key, TCO_VERBATIM[key])
+
 #: Genesys/Broadreach deployment schedule (slides 17-21), months from
 #: Jan 2026 inclusive. Benefits realize IMPL + 3 months.
 IMPL_MONTH = {"NA": 18, "ANZ": 21, "EMEA": 24, "ASIA": 27}