Adapt economics dashboard to sole-member zero-cost reality

Update membership, revenue, and cost registries to one active member with
no running costs. Refresh dashboard report and tests for €8.99 revenue and
100% gross margin.

projects/coulomb-pricing/tests/test_economics.py

@@ -17,10 +17,10 @@ DATA_DIR = Path(__file__).resolve().parent.parent / "data"
 
 def test_active_members_counts_only_active_status() -> None:
     members = load_membership(DATA_DIR)
-    assert active_members(members) == 3
+    assert active_members(members) == 1
 
 
-def test_build_snapshot_uses_seed_revenue_for_period() -> None:
+def test_build_snapshot_reflects_sole_member_and_zero_costs() -> None:
     product = load_product(DATA_DIR)
     models = load_pricing_models(DATA_DIR)
     members = load_membership(DATA_DIR)
@@ -29,23 +29,20 @@ def test_build_snapshot_uses_seed_revenue_for_period() -> None:
 
     snapshot = build_snapshot("2026-06", product, models, members, revenue, costs, fx_rates)
 
-    assert snapshot.active_members == 3
-    assert snapshot.monthly_revenue == Decimal("80.91")
-    assert snapshot.revenue_source == "manual_estimate"
+    assert snapshot.active_members == 1
+    assert snapshot.monthly_revenue == Decimal("8.99")
+    assert snapshot.revenue_source == "manual"
     assert snapshot.pricing_model_count == 3
-    assert snapshot.monthly_cost > Decimal("0")
-    assert snapshot.cost_per_member == (snapshot.monthly_cost / 3).quantize(Decimal("0.01"))
-    assert snapshot.gross_margin == (snapshot.monthly_revenue - snapshot.monthly_cost).quantize(
-        Decimal("0.01")
-    )
+    assert snapshot.monthly_cost == Decimal("0.00")
+    assert snapshot.cost_per_member == Decimal("0.00")
+    assert snapshot.gross_margin == Decimal("8.99")
+    assert snapshot.gross_margin_pct == Decimal("100.0")
 
 
-def test_monthly_cost_includes_fixed_and_variable_components() -> None:
+def test_monthly_cost_is_zero_with_empty_registry() -> None:
     _, costs, fx_rates = load_costs(DATA_DIR)
-    total = monthly_cost_total(costs, fx_rates, Decimal("80.91"), 3)
-    # fixed: 35 USD -> 32.20 EUR + 15 EUR + 25 EUR = 72.20
-    # variable: 1.5% of 80.91 + 0.25 * 3 = 1.21 + 0.75 = 1.96
-    assert total == Decimal("74.16")
+    total = monthly_cost_total(costs, fx_rates, Decimal("8.99"), 1)
+    assert total == Decimal("0.00")
 
 
 def test_dashboard_module_renders_markdown() -> None:
@@ -54,4 +51,5 @@ def test_dashboard_module_renders_markdown() -> None:
     report = generate_dashboard(DATA_DIR, "2026-06")
     assert "# Economics Dashboard v1" in report
     assert "Pricing Model Registry" in report
-    assert "flat-899-eur-monthly" in report
+    assert "flat-899-eur-monthly" in report
+    assert "Active members | 1" in report