update notebook to use staging steps instead of SQL hack

Remove the inline core.medical_claim → core.condition SQL JOIN from
load() — the pipeline's _stg_medical_claim and _stg_medical_claim_condition
steps handle diagnosis code enrichment now. Add staging steps to the
UAMCC pipeline execution and walkthrough sections.

notebooks/cms_quality_measures.py

@@ -138,6 +138,8 @@ def _(ex, inspect, mo):
 @app.cell(hide_code=True)
 def _(ex, fn_doc, mo):
     _uamcc_steps = [
+        ("0a. Stage Medical Claims", ex.stg_medical_claim),
+        ("0b. Stage Claim–Condition Pairs", ex.stg_medical_claim_condition),
         ("1. Performance Period", ex.uamcc_performance_period),
         ("2. MCC Cohort Identification", ex.uamcc_int_mcc_cohort),
         ("3. Denominator", ex.uamcc_int_denominator),
@@ -657,18 +659,6 @@ def _(con, inspect, mo, pl):
 
     def load(table_ref):
         """Load a table from DuckDB, with fallbacks for missing tables."""
-        # Enrich core.medical_claim with diagnosis codes from core.condition
-        if table_ref == "core.medical_claim":
-            return con.execute("""
-                SELECT m.*,
-                       c.normalized_code,
-                       c.normalized_code AS principal_diagnosis_code
-                FROM core.medical_claim m
-                LEFT JOIN core.condition c
-                    ON m.claim_id = c.claim_id
-                    AND c.condition_rank = 1
-            """).pl()
-
         _schema, _tbl = table_ref.split(".", 1)
         try:
             _df = con.execute(f'SELECT * FROM "{_schema}"."{_tbl}"').pl()
@@ -724,6 +714,8 @@ Running all three measure pipelines against **Synthea/Tuva claims data**
 @app.cell(hide_code=True)
 def _(ex, mo, pl, run_step, uamcc_pp):
     _uamcc_pipeline = [
+        ("cms_quality_measures._stg_medical_claim", ex.stg_medical_claim),
+        ("cms_quality_measures._stg_medical_claim_condition", ex.stg_medical_claim_condition),
         ("cms_quality_measures._uamcc_performance_period", ex.uamcc_performance_period),
         ("cms_quality_measures._uamcc_int_mcc_cohort", ex.uamcc_int_mcc_cohort),
         ("cms_quality_measures._uamcc_int_denominator", ex.uamcc_int_denominator),