Refactor economics to expense-record ledger with correct Bubble cost

Replace pre-aggregated costs.json with expense_records.json (48 line-item
records) and payment_records.json. All monthly and cumulative totals are
computed deterministically in observatory/ledger.py. Correct Bubble.io to
$32/mo (since Feb 2025) — infrastructure €69.44/mo not €72.20.

projects/coulomb-pricing/tests/test_economics.py

@@ -3,20 +3,17 @@ from __future__ import annotations
 from decimal import Decimal
 from pathlib import Path
 
-from observatory.economics import (
-    active_members,
-    build_liquidity_summary,
-    build_snapshot,
-    monthly_cost_from_rate_card,
-)
+from observatory.economics import active_members, build_liquidity_summary, build_snapshot
+from observatory.ledger import aggregate_infrastructure_by_period, build_monthly_ledger
 from observatory.load import (
     load_budget,
-    load_cost_rate_card,
+    load_expense_records,
+    load_fx_rates,
     load_membership,
-    load_monthly_platform_costs,
+    load_monthly_ledger,
+    load_payment_records,
     load_pricing_models,
     load_product,
-    load_revenue,
 )
 
 DATA_DIR = Path(__file__).resolve().parent.parent / "data"
@@ -27,52 +24,80 @@ def test_active_members_counts_only_active_status() -> None:
     assert active_members(members) == 1
 
 
-def test_rate_card_splits_infrastructure_and_payment_processing() -> None:
-    rate_card, fx_rates = load_cost_rate_card(DATA_DIR)
-    infrastructure = monthly_cost_from_rate_card(rate_card, fx_rates, Decimal("0"), 0)
-    with_revenue = monthly_cost_from_rate_card(rate_card, fx_rates, Decimal("8.99"), 1)
-    assert infrastructure == Decimal("72.20")
-    assert with_revenue == Decimal("72.58")
-    assert with_revenue - infrastructure == Decimal("0.38")
+def test_infrastructure_aggregated_from_expense_records() -> None:
+    expenses = load_expense_records(DATA_DIR)
+    fx = load_fx_rates(DATA_DIR)
+    totals = aggregate_infrastructure_by_period(expenses, fx)
+
+    assert totals["2025-03"] == Decimal("69.44")
+    assert totals["2026-06"] == Decimal("69.44")
+    # Bubble $32 @ 0.92 = 29.44 + 15 domains + 25 overhead
+    bubble_eur = Decimal("32.00") * Decimal("0.92")
+    assert bubble_eur == Decimal("29.44")
 
 
-def test_build_snapshot_june_2026_avoids_stripe_double_count_in_liquidity() -> None:
+def test_monthly_ledger_computes_processing_from_payment_records() -> None:
+    ledger = load_monthly_ledger(DATA_DIR)
+    june = next(row for row in ledger if row.period == "2026-06")
+    march = next(row for row in ledger if row.period == "2025-03")
+
+    assert march.infrastructure_cost == Decimal("69.44")
+    assert march.payment_processing_cost == Decimal("0.00")
+    assert march.gross_revenue == Decimal("0.00")
+    assert june.infrastructure_cost == Decimal("69.44")
+    assert june.payment_processing_cost == Decimal("0.38")
+    assert june.gross_revenue == Decimal("8.99")
+
+
+def test_build_snapshot_june_2026_uses_ledger_not_hand_totals() -> None:
     product = load_product(DATA_DIR)
     models = load_pricing_models(DATA_DIR)
     members = load_membership(DATA_DIR)
-    revenue = load_revenue(DATA_DIR)
-    monthly_costs = load_monthly_platform_costs(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    ledger = load_monthly_ledger(DATA_DIR)
 
-    snapshot = build_snapshot("2026-06", product, models, members, revenue, monthly_costs)
+    snapshot = build_snapshot("2026-06", product, models, members, payments, ledger)
 
-    assert snapshot.monthly_infrastructure_cost == Decimal("72.20")
+    assert snapshot.monthly_infrastructure_cost == Decimal("69.44")
     assert snapshot.monthly_payment_processing_cost == Decimal("0.38")
-    assert snapshot.monthly_total_platform_cost == Decimal("72.58")
-    assert snapshot.period_net_liquidity == Decimal("-63.59")
-    assert snapshot.gross_margin == Decimal("-63.59")
+    assert snapshot.monthly_total_platform_cost == Decimal("69.82")
+    assert snapshot.period_net_liquidity == Decimal("-60.83")
+    assert snapshot.gross_margin == Decimal("-60.83")
 
 
-def test_liquidity_summary_uses_infrastructure_only_for_cumulative_burn() -> None:
+def test_liquidity_summary_aggregates_ledgers_deterministically() -> None:
     budget = load_budget(DATA_DIR)
-    revenue = load_revenue(DATA_DIR)
-    monthly_costs = load_monthly_platform_costs(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    ledger = load_monthly_ledger(DATA_DIR)
 
-    summary = build_liquidity_summary(budget, revenue, monthly_costs, "2026-06")
+    summary = build_liquidity_summary(budget, payments, ledger, "2026-06")
 
-    assert summary.cumulative_infrastructure_cost == Decimal("1155.20")
+    assert summary.cumulative_infrastructure_cost == Decimal("1111.04")
     assert summary.cumulative_payment_processing_cost == Decimal("3.04")
-    assert summary.cumulative_total_platform_cost == Decimal("1158.24")
+    assert summary.cumulative_total_platform_cost == Decimal("1114.08")
     assert summary.cumulative_member_payments == Decimal("68.88")
-    assert summary.cumulative_net_liquidity == Decimal("-1086.32")
-    assert summary.remaining_budget == Decimal("-86.32")
+    assert summary.cumulative_net_liquidity == Decimal("-1042.16")
+    assert summary.remaining_budget == Decimal("-42.16")
     assert summary.liquidity_status == "burning"
     assert summary.months_tracked == 16
 
 
-def test_dashboard_renders_split_cost_columns() -> None:
+def test_build_monthly_ledger_matches_loader() -> None:
+    budget = load_budget(DATA_DIR)
+    expenses = load_expense_records(DATA_DIR)
+    payments = load_payment_records(DATA_DIR)
+    members = load_membership(DATA_DIR)
+    fx = load_fx_rates(DATA_DIR)
+
+    assert build_monthly_ledger(budget, expenses, payments, members, fx) == load_monthly_ledger(
+        DATA_DIR
+    )
+
+
+def test_dashboard_notes_expense_record_source() -> None:
     from observatory.dashboard import generate_dashboard
 
     report = generate_dashboard(DATA_DIR, "2026-06")
-    assert "Cumulative infrastructure cost" in report
-    assert "1155.20" in report
-    assert "-86.32" in report
+    assert "expense and payment record ledgers" in report
+    assert "1111.04" in report
+    assert "-42.16" in report