efficient-did: complete cluster_name rename propagation + suppress duplicate Bootstrap summary line

Two follow-up fixes:

1. cluster → cluster_name propagation. The original PR renamed the
   EfficientDiDResults.cluster field to cluster_name but left two
   consumers still referencing the old name:
   - tests/test_business_report.py:1267 (TestHausmanPretestPropagatesCluster
     regression test asserting the field is persisted for the Hausman
     pretest replay) — updated assertion + class docstring.
   - docs/api/_autosummary/diff_diff.EfficientDiDResults.rst — the
     checked-in Sphinx autosummary still listed cluster and was missing
     cluster_name, n_clusters, vcov_type, and the new to_dict() method.

2. Suppress duplicate Bootstrap summary header. EfficientDiDResults.summary()
   previously emitted both the legacy "Bootstrap: <n> (<weights>)" header
   line (L250-L251 pre-PR) and the new "Inference method: bootstrap" +
   "Bootstrap replications: <n>" block. The legacy header is now gated on
   `bootstrap_results is None` so analytical-only fits keep the original
   render and bootstrap-overwritten fits use the canonical inference-method
   block alone (matches the sibling result-container convention).

211 tests pass across test_efficient_did.py, test_efficient_did_validation.py,
test_diagnostics.py, and test_business_report.py::TestHausmanPretestPropagatesCluster.
black + ruff clean on touched Python files.

Author: igerber

diff_diff/efficient_did_results.py

@@ -247,7 +247,11 @@ def summary(self, alpha: Optional[float] = None) -> str:
             lines.append(f"{'Control group:':<30} {self.control_group:>10}")
         if self.anticipation > 0:
             lines.append(f"{'Anticipation periods:':<30} {self.anticipation:>10}")
-        if self.n_bootstrap > 0:
+        # Suppress the legacy ``Bootstrap:`` header when ``bootstrap_results``
+        # is present — the new variance/inference-method block below renders
+        # the canonical ``Inference method: bootstrap`` + ``Bootstrap
+        # replications:`` lines, so the old header would duplicate metadata.
+        if self.n_bootstrap > 0 and self.bootstrap_results is None:
             lines.append(f"{'Bootstrap:':<30} {self.n_bootstrap:>10} ({self.bootstrap_weights})")
         lines.append("")
 

docs/api/_autosummary/diff_diff.EfficientDiDResults.rst

@@ -15,6 +15,7 @@
       ~EfficientDiDResults.print_summary
       ~EfficientDiDResults.summary
       ~EfficientDiDResults.to_dataframe
+      ~EfficientDiDResults.to_dict
 
 
 
@@ -28,7 +29,7 @@
       ~EfficientDiDResults.att
       ~EfficientDiDResults.bootstrap_results
       ~EfficientDiDResults.bootstrap_weights
-      ~EfficientDiDResults.cluster
+      ~EfficientDiDResults.cluster_name
       ~EfficientDiDResults.coef_var
       ~EfficientDiDResults.conf_int
       ~EfficientDiDResults.control_group
@@ -40,6 +41,7 @@
       ~EfficientDiDResults.is_significant
       ~EfficientDiDResults.kernel_bandwidth
       ~EfficientDiDResults.n_bootstrap
+      ~EfficientDiDResults.n_clusters
       ~EfficientDiDResults.omega_condition_numbers
       ~EfficientDiDResults.p_value
       ~EfficientDiDResults.pt_assumption
@@ -51,6 +53,7 @@
       ~EfficientDiDResults.significance_stars
       ~EfficientDiDResults.survey_metadata
       ~EfficientDiDResults.t_stat
+      ~EfficientDiDResults.vcov_type
       ~EfficientDiDResults.group_time_effects
       ~EfficientDiDResults.overall_att
       ~EfficientDiDResults.overall_se

tests/test_business_report.py

@@ -1242,7 +1242,7 @@ def test_survey_weighted_fit_skipped_with_reason(self):
 
 class TestHausmanPretestPropagatesCluster:
     """Round-11 regression: ``EfficientDiDResults`` now persists the
-    ``cluster`` column used at fit time, and ``_pt_hausman`` forwards
+    ``cluster_name`` column used at fit time, and ``_pt_hausman`` forwards
     it to ``EfficientDiD.hausman_pretest``. Without this, clustered
     fits would be replayed under unclustered inference, silently
     publishing an H statistic / p-value for the wrong design.
@@ -1266,7 +1266,7 @@ def test_hausman_pretest_receives_cluster_kwarg(self):
             first_treat="first_treat",
         )
         # Confirm persistence landed.
-        assert getattr(edid, "cluster", None) == "cluster_col"
+        assert getattr(edid, "cluster_name", None) == "cluster_col"
 
         captured: dict = {}