refactor(cli): delegate paceENSDF config building to library

Remove the duplicated inline paceENSDF config builder in the CLI.
It renormalized branch intensities before filtering, diverging from
the library decay_info_to_config path that library callers use
(audit finding D5). CLI paceENSDF configs now come from
create_config_from_source exactly once per run.

Regression test spies on create_config_from_source during a CLI run.

beta_spectrum/cli.py

@@ -178,15 +178,10 @@ def _run(args: argparse.Namespace) -> None:
     from beta_spectrum.logging_utils import get_logger
     from beta_spectrum.nuclear_data import (
         create_config_from_source,
-        get_decay_info_from_paceENSDF,
         json_to_config,
         load_json_input,
     )
-    from beta_spectrum.spectrum import (
-        BetaSpectrum,
-        BranchConfig,
-        SpectrumConfig,
-    )
+    from beta_spectrum.spectrum import BetaSpectrum
     from beta_spectrum.output import BetaSpectrumAnalyzer
 
     # Determine logging level
@@ -246,62 +241,19 @@ def _run(args: argparse.Namespace) -> None:
     csv_separator = "," if args.csv_separator is None else args.csv_separator
     normalize_to_one = bool(args.normalize_to_one)
 
-    # Build config
+    # Build config — a single delegated path for every data source.
     config: SpectrumConfig
     if source_type == "paceENSDF":
         logger.info("Source: paceENSDF nuclide=%s", source_value)
-        decay_info = get_decay_info_from_paceENSDF(source_value, "beta_minus")
-
-        # Normalize branch intensities to sum to 1.0
-        if decay_info.branches:
-            total_intensity = sum(b.intensity for b in decay_info.branches)
-            if total_intensity > 0:
-                branches = [
-                    BranchConfig(
-                        endpoint_MeV=(
-                            (decay_info.endpoint_MeV - b.level_energy_keV / 1000.0)
-                            if b.level_energy_keV > 0
-                            else decay_info.endpoint_MeV
-                        ),
-                        transition_type=b.transition_type,
-                        intensity=b.intensity / total_intensity,
-                    )
-                    for b in decay_info.branches
-                    if b.intensity / total_intensity >= intensity_cutoff
-                ]
-                config = SpectrumConfig(
-                    Z_parent=decay_info.Z_parent,
-                    Z_daughter=decay_info.Z_daughter,
-                    A_number=decay_info.A_number,
-                    endpoint_MeV=decay_info.endpoint_MeV,
-                    transition_type=decay_info.transition_type,
-                    e_step_MeV=e_step_MeV,
-                    neutrino_mass_MeV=neutrino_mass_MeV,
-                    branches=branches,
-                    intensity_cutoff=intensity_cutoff,
-                    csv_separator=csv_separator,
-                    normalize_to_one=normalize_to_one,
-                )
-            else:
-                config = create_config_from_source(
-                    "paceENSDF",
-                    nuclide=source_value,
-                    e_step_MeV=e_step_MeV,
-                    intensity_cutoff=intensity_cutoff,
-                    neutrino_mass_MeV=neutrino_mass_MeV,
-                    csv_separator=csv_separator,
-                    normalize_to_one=normalize_to_one,
-                )
-        else:
-            config = create_config_from_source(
-                "paceENSDF",
-                nuclide=source_value,
-                e_step_MeV=e_step_MeV,
-                intensity_cutoff=intensity_cutoff,
-                neutrino_mass_MeV=neutrino_mass_MeV,
-                csv_separator=csv_separator,
-                normalize_to_one=normalize_to_one,
-            )
+        config = create_config_from_source(
+            "paceENSDF",
+            nuclide=source_value,
+            e_step_MeV=e_step_MeV,
+            intensity_cutoff=intensity_cutoff,
+            neutrino_mass_MeV=neutrino_mass_MeV,
+            csv_separator=csv_separator,
+            normalize_to_one=normalize_to_one,
+        )
     else:
         logger.info("Source: JSON file=%s", source_value)
         data = load_json_input(source_value)