diff --git a/tests/phase_12/test_proc_audio_descriptor_routing_contract_additional.py b/tests/phase_12/test_proc_audio_descriptor_routing_contract_additional.py
new file mode 100644
index 0000000..ce922f8
--- /dev/null
+++ b/tests/phase_12/test_proc_audio_descriptor_routing_contract_additional.py
@@ -0,0 +1,404 @@
+from __future__ import annotations
+
+"""
+Seventh Phase 12 descriptor / export-routing contract layer for proc_audio.py.
+
+Complements test_proc_audio_core_additional.py,
+test_proc_audio_helper_contract_additional.py, and
+test_proc_audio_preprocessing_contract_additional.py with helper-level
+regression tests for H/I/S separation, canonical vs body-band vs
+full-spectrum vs diagnostic descriptor routing, and export-row preparation
+before compile_metrics.
+
+No production code changes. No real audio, GUI, plotting, or batch pipeline.
+"""
+
+from copy import deepcopy
+
+import math
+
+import numpy as np
+import pytest
+
+import proc_audio as PA
+from proc_audio import AudioProcessor
+
+
+def _export_ap(**attrs: object) -> AudioProcessor:
+    ap = AudioProcessor()
+    ap.weight_function = "log"
+    ap.density_salience_threshold_db = -40.0
+    ap.density_frequency_ceiling_hz = 5000.0
+    ap.freq_max = 20000.0
+    for key, val in attrs.items():
+        setattr(ap, key, val)
+    return ap
+
+
+def _main_row(
+    ap: AudioProcessor,
+    *,
+    note: str = "C4",
+    h_psum: float = 2.0,
+    i_psum: float = 1.0,
+    s_psum: float = 0.5,
+    t_psum: float = 3.5,
+) -> dict:
+    return ap._build_main_metrics_export_row(
+        note,
+        h_psum=h_psum,
+        i_psum=i_psum,
+        s_psum=s_psum,
+        t_psum=t_psum,
+    )
+
+
+# ---------------------------------------------------------------------------
+# 1. Canonical / body-band / full-spectrum separation in export row
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_keeps_canonical_body_and_full_spectrum_scalars_separate() -> None:
+    ap = _export_ap(
+        canonical_density_v5_adapted=1.25,
+        effective_partial_density=3.0,
+        harmonic_body_density=0.55,
+        density_body_weighted_sum_body_ceiling=99.0,
+        density_full_spectrum_weighted_sum_20khz=88.0,
+        harmonic_full_spectrum_energy_sum_20khz=7.0,
+        harmonic_component_energy_sum_body_ceiling=4.0,
+    )
+    row = _main_row(ap)
+    assert row["canonical_density_v5_adapted"] == pytest.approx(1.25)
+    assert row["effective_partial_density"] == pytest.approx(3.0)
+    assert row["harmonic_body_density"] == pytest.approx(0.55)
+    assert row["density_body_weighted_sum_body_ceiling"] == pytest.approx(99.0)
+    assert row["density_full_spectrum_weighted_sum_20khz"] == pytest.approx(88.0)
+    assert row["harmonic_full_spectrum_energy_sum_20khz"] == pytest.approx(7.0)
+    assert row["harmonic_component_energy_sum_body_ceiling"] == pytest.approx(4.0)
+    assert row["density_body_weighted_sum_body_ceiling"] != pytest.approx(row["canonical_density_v5_adapted"])
+
+
+def test_export_row_body_ceiling_does_not_replace_effective_partial_density() -> None:
+    ap = _export_ap(
+        effective_partial_density=2.75,
+        body_weighted_effective_density=1.1,
+        density_body_weighted_sum_body_ceiling=50.0,
+        pitch_normalized_component_body_density_body_ceiling=0.33,
+    )
+    row = _main_row(ap)
+    assert row["effective_partial_density"] == pytest.approx(2.75)
+    assert row["body_weighted_effective_density"] == pytest.approx(1.1)
+    assert row["density_body_weighted_sum_body_ceiling"] == pytest.approx(50.0)
+    assert row["pitch_normalized_component_body_density_body_ceiling"] == pytest.approx(0.33)
+
+
+# ---------------------------------------------------------------------------
+# 2. H/I/S routing in export row and pie helpers
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_partial_sums_use_arguments_not_attached_energy_scalars() -> None:
+    ap = _export_ap(
+        harmonic_energy_sum=999.0,
+        inharmonic_energy_sum=888.0,
+        subbass_energy_sum=777.0,
+    )
+    row = _main_row(ap, h_psum=2.0, i_psum=1.0, s_psum=0.25, t_psum=3.25)
+    assert row["Harmonic Partials sum"] == pytest.approx(2.0)
+    assert row["Inharmonic Partials sum"] == pytest.approx(1.0)
+    assert row["Sub-bass sum"] == pytest.approx(0.25)
+    assert row["Total sum"] == pytest.approx(3.25)
+    assert row["harmonic_energy_sum"] == pytest.approx(999.0)
+    assert row["inharmonic_energy_sum"] == pytest.approx(888.0)
+    assert row["subbass_energy_sum"] == pytest.approx(777.0)
+
+
+def test_export_row_his_energy_ratios_remain_distinct_from_component_aliases() -> None:
+    ap = _export_ap(
+        harmonic_energy_ratio=0.60,
+        inharmonic_energy_ratio=0.30,
+        subbass_energy_ratio=0.10,
+        component_harmonic_energy_ratio=0.99,
+        component_inharmonic_energy_ratio=0.01,
+        component_subbass_energy_ratio=0.0,
+    )
+    row = _main_row(ap)
+    assert row["harmonic_energy_ratio"] == pytest.approx(0.60)
+    assert row["inharmonic_energy_ratio"] == pytest.approx(0.30)
+    assert row["subbass_energy_ratio"] == pytest.approx(0.10)
+    assert row["component_harmonic_energy_ratio"] == pytest.approx(0.99)
+    assert row["component_inharmonic_energy_ratio"] == pytest.approx(0.01)
+    assert row["component_subbass_energy_ratio"] == pytest.approx(0.0)
+
+
+def test_component_energy_ratio_triple_preserves_his_order_and_uses_primary() -> None:
+    ap = _export_ap(
+        harmonic_energy_ratio=0.60,
+        inharmonic_energy_ratio=0.30,
+        subbass_energy_ratio=0.10,
+        component_harmonic_energy_ratio=0.99,
+        component_inharmonic_energy_ratio=0.01,
+        component_subbass_energy_ratio=0.0,
+    )
+    trip, primary_missing, fb_missing = ap._component_energy_ratio_triple_for_pie()
+    assert trip == (0.60, 0.30, 0.10)
+    assert primary_missing == []
+    assert fb_missing == []
+
+
+def test_component_energy_ratio_triple_falls_back_to_component_aliases_when_primary_missing() -> None:
+    ap = _export_ap(
+        component_harmonic_energy_ratio=0.50,
+        component_inharmonic_energy_ratio=0.40,
+        component_subbass_energy_ratio=0.10,
+    )
+    trip, primary_missing, fb_missing = ap._component_energy_ratio_triple_for_pie()
+    assert trip == (0.50, 0.40, 0.10)
+    assert "harmonic_energy_ratio" in primary_missing
+    assert "inharmonic_energy_ratio" in primary_missing
+
+
+def test_component_energy_ratio_triple_empty_container_returns_none() -> None:
+    ap = AudioProcessor()
+    trip, primary_missing, fb_missing = ap._component_energy_ratio_triple_for_pie()
+    assert trip is None
+    assert "harmonic_energy_ratio" in primary_missing
+    assert "component_harmonic_energy_ratio" in fb_missing
+
+
+# ---------------------------------------------------------------------------
+# 3. Canonical vs diagnostic density descriptors
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_diagnostic_density_falls_back_to_density_metric_value() -> None:
+    ap = _export_ap(
+        canonical_density_v5_adapted=1.50,
+        density_metric_value=3.30,
+    )
+    row = _main_row(ap)
+    assert row["canonical_density_v5_adapted"] == pytest.approx(1.50)
+    assert row["energy_weighted_component_density_diagnostic"] == pytest.approx(3.30)
+
+
+def test_export_row_explicit_diagnostic_does_not_replace_canonical_density() -> None:
+    ap = _export_ap(
+        canonical_density_v5_adapted=1.50,
+        energy_weighted_component_density_diagnostic=9.99,
+        density_metric_value=3.30,
+    )
+    row = _main_row(ap)
+    assert row["canonical_density_v5_adapted"] == pytest.approx(1.50)
+    assert row["energy_weighted_component_density_diagnostic"] == pytest.approx(9.99)
+
+
+def test_export_row_legacy_component_strength_aliases_remain_separate() -> None:
+    ap = _export_ap(
+        component_strength_h=0.7,
+        component_strength_i=0.2,
+        component_strength_s=0.1,
+        legacy_component_strength_h_v55=0.99,
+        legacy_component_strength_i_v55=0.01,
+        legacy_component_strength_s_v55=0.0,
+    )
+    row = _main_row(ap)
+    assert row["component_strength_h"] == pytest.approx(0.7)
+    assert row["legacy_component_strength_h_v55"] == pytest.approx(0.99)
+
+
+# ---------------------------------------------------------------------------
+# 4. Legacy export row vs main metrics export row
+# ---------------------------------------------------------------------------
+
+
+def test_build_legacy_density_metrics_row_uses_legacy_keys_and_canonical_preference() -> None:
+    ap = _export_ap(
+        canonical_density_v5_adapted=2.0,
+        density_metric_value=9.0,
+        spectral_density_metric_value=1.1,
+        filtered_density_metric_value=0.8,
+        combined_density_metric_value=1.5,
+    )
+    legacy = ap._build_legacy_density_metrics_row("D4")
+    assert set(legacy.keys()) == {
+        "Note",
+        "weight_function",
+        "Density Metric",
+        "Spectral Density Metric",
+        "Filtered Density Metric",
+        "Combined Density Metric",
+        "spectral_masking_enabled",
+        "legacy_density_export_version",
+    }
+    assert legacy["Density Metric"] == pytest.approx(2.0)
+    assert legacy["Spectral Density Metric"] == pytest.approx(1.1)
+    assert "canonical_density_v5_adapted" not in legacy
+
+
+def test_build_legacy_density_metrics_row_falls_back_to_density_metric_value() -> None:
+    ap = _export_ap(density_metric_value=4.5)
+    legacy = ap._build_legacy_density_metrics_row("G4")
+    assert legacy["Density Metric"] == pytest.approx(4.5)
+
+
+# ---------------------------------------------------------------------------
+# 5. Amplitude-mass routing priority (diagnostic vs linear fallback)
+# ---------------------------------------------------------------------------
+
+
+def test_preferred_component_amplitude_sum_triple_requires_all_three_finite_positive() -> None:
+    ap = _export_ap(
+        harmonic_amplitude_sum=2.0,
+        inharmonic_amplitude_sum=1.0,
+    )
+    assert ap._preferred_component_amplitude_sum_triple() is None
+
+
+def test_component_amplitude_mass_triple_falls_back_to_linear_sums_when_preferred_missing() -> None:
+    ap = _export_ap(
+        linear_sum_amplitude_harmonic=2.0,
+        linear_sum_amplitude_inharmonic_partial=1.0,
+        linear_sum_amplitude_subbass_band=0.5,
+    )
+    triple, basis, gaps, tech = ap._component_amplitude_mass_triple_for_pie()
+    assert triple == (2.0, 1.0, 0.5)
+    assert basis == "linear_amplitude_sum"
+    assert "harmonic_amplitude_sum" in gaps
+    assert tech == "linear_sum_amplitude_metrics"
+
+
+def test_linear_component_density_balance_triple_uses_named_linear_sums() -> None:
+    ap = _export_ap(
+        linear_sum_amplitude_harmonic=1.0,
+        linear_sum_amplitude_inharmonic_partial=0.5,
+        linear_sum_amplitude_subbass_band=0.25,
+    )
+    h, i, s, basis = ap._linear_component_density_balance_triple_with_basis()
+    assert (h, i, s) == (1.0, 0.5, 0.25)
+    assert basis == "linear_sum_amplitude_metrics"
+
+
+# ---------------------------------------------------------------------------
+# 6. Parameter provenance / metadata in export row
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_f0_provenance_fields_reflect_canonical_triplet() -> None:
+    ap = _export_ap(
+        f0_final=261.63,
+        f0_initial=260.0,
+        f0_prior_hz=258.0,
+        f0_fit_accepted=True,
+        f0_final_source="robust_fit",
+        acoustic_f0_status="accepted_robust",
+        f0_validation_mode="free_fit",
+    )
+    row = _main_row(ap)
+    assert row["Note"] == "C4"
+    assert row["f0_used_for_density_hz"] == pytest.approx(261.63)
+    assert row["f0_used_for_density_source"] == "robust_fit"
+    assert row["f0_final_hz"] == pytest.approx(261.63)
+    assert row["weight_function"] == "log"
+
+
+def test_export_row_analysis_parameter_profile_id_is_deterministic() -> None:
+    ap = _export_ap(
+        weight_function="log",
+        density_salience_threshold_db=-40.0,
+        density_frequency_ceiling_hz=5000.0,
+    )
+    first = _main_row(ap)["analysis_parameter_profile_id"]
+    second = _main_row(ap)["analysis_parameter_profile_id"]
+    assert first == second == "wf=log|dst=-40.0|ceil=5000.0"
+
+
+def test_export_row_includes_density_metric_contract_metadata() -> None:
+    row = _main_row(_export_ap())
+    assert row["metric_contract_name"] == "density_metric_raw"
+    assert row["metric_contract_formula"] == "D_H*w_H + D_I*w_I + D_S*w_S"
+    assert row["metric_contract_basis"] == "log-amplitude"
+
+
+def test_export_row_does_not_leak_runtime_path_keys() -> None:
+    ap = _export_ap()
+    ap.folder_path = "C:\\Users\\secret\\audio_batch"
+    row = _main_row(ap)
+    forbidden = {"cwd", "proc_audio_file", "folder_path", "sys_executable"}
+    assert forbidden.isdisjoint(row.keys())
+    for val in row.values():
+        if isinstance(val, str) and ("\\Users\\" in val or ":/" in val):
+            pytest.fail(f"unexpected path-like export value: {val!r}")
+
+
+# ---------------------------------------------------------------------------
+# 7. Numeric stability and missing-value fallbacks
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_missing_optional_numeric_fields_become_nan() -> None:
+    row = _main_row(_export_ap())
+    assert math.isnan(row["harmonic_body_density"])
+    assert math.isnan(row["density_full_spectrum_weighted_sum_20khz"])
+    assert math.isnan(row["density_metric_normalized"])
+
+
+def test_export_row_finite_numeric_fields_remain_float() -> None:
+    ap = _export_ap(
+        harmonic_density_component=1.2,
+        inharmonic_density_component=0.4,
+        subbass_density_component=0.1,
+        harmonic_density_component_on_attack=0.9,
+    )
+    row = _main_row(ap)
+    assert isinstance(row["harmonic_density_component"], float)
+    assert row["harmonic_density_component_on_attack"] == pytest.approx(0.9)
+
+
+def test_export_row_nonfinite_attached_scalars_sanitize_to_nan() -> None:
+    ap = _export_ap(
+        harmonic_energy_ratio=float("inf"),
+        inharmonic_energy_sum=float("nan"),
+        harmonic_amplitude_sum=None,
+    )
+    row = _main_row(ap)
+    assert math.isnan(row["harmonic_energy_ratio"])
+    assert math.isnan(row["inharmonic_energy_sum"])
+
+
+# ---------------------------------------------------------------------------
+# 8. Determinism / non-mutation
+# ---------------------------------------------------------------------------
+
+
+def test_export_row_builder_is_idempotent_and_preserves_attached_scalars() -> None:
+    ap = _export_ap(
+        canonical_density_v5_adapted=1.8,
+        harmonic_energy_ratio=0.65,
+        inharmonic_energy_ratio=0.25,
+        subbass_energy_ratio=0.10,
+    )
+    snap = deepcopy(
+        {
+            "canonical_density_v5_adapted": ap.canonical_density_v5_adapted,
+            "harmonic_energy_ratio": ap.harmonic_energy_ratio,
+        }
+    )
+    first = _main_row(ap)
+    second = _main_row(ap)
+    assert first == second
+    assert ap.canonical_density_v5_adapted == snap["canonical_density_v5_adapted"]
+    assert ap.harmonic_energy_ratio == snap["harmonic_energy_ratio"]
+
+
+def test_publication_clean_export_adds_canonical_density_alias_without_dropping_canonical_v5() -> None:
+    ap = _export_ap(canonical_density_v5_adapted=2.2, density_formula_version="v5_test")
+    with pytest.MonkeyPatch.context() as mp:
+        mp.setattr(
+            "metadata_sanitizer.publication_clean_export_enabled",
+            lambda: True,
+        )
+        row = _main_row(ap)
+    assert row["canonical_density_v5_adapted"] == pytest.approx(2.2)
+    assert row["canonical_density"] == pytest.approx(2.2)
+    assert "density_formula_version" not in row