Add liquidity tracking, budget, and platform cost history

Restore operator platform costs (Bubble, domains, Stripe) with monthly
history from March 2025 and member payments from November 2025. Track
€1,000 starting budget, cumulative burn, and remaining liquidity in the
economics dashboard. Document LQ requirements in REQUIREMENTS.md.

projects/coulomb-pricing/observatory/load.py

@@ -5,8 +5,10 @@ from decimal import Decimal
 from pathlib import Path
 
 from .models import (
+    Budget,
     CostEntry,
     MembershipRecord,
+    MonthlyPlatformCost,
     PricingModel,
     Product,
     RevenueEntry,
@@ -37,6 +39,15 @@ def load_product(data_dir: Path | None = None) -> Product:
     )
 
 
+def load_budget(data_dir: Path | None = None) -> Budget:
+    raw = _read_json((data_dir or default_data_dir()) / "budget.json")
+    return Budget(
+        currency=raw["currency"],
+        initial_budget=_money(raw["initial_budget"]),
+        started=raw["started"],
+    )
+
+
 def load_pricing_models(data_dir: Path | None = None) -> list[PricingModel]:
     raw = _read_json((data_dir or default_data_dir()) / "pricing-models.json")
     return [
@@ -54,9 +65,8 @@ def load_pricing_models(data_dir: Path | None = None) -> list[PricingModel]:
     ]
 
 
-def load_costs(data_dir: Path | None = None) -> tuple[str, list[CostEntry], dict[str, Decimal]]:
-    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
-    entries = [
+def _parse_cost_entries(items: list[dict]) -> list[CostEntry]:
+    return [
         CostEntry(
             id=item["id"],
             name=item["name"],
@@ -66,10 +76,28 @@ def load_costs(data_dir: Path | None = None) -> tuple[str, list[CostEntry], dict
             cadence=item["cadence"],
             allocation=item["allocation"],
         )
-        for item in raw["entries"]
+        for item in items
     ]
+
+
+def load_cost_rate_card(data_dir: Path | None = None) -> tuple[list[CostEntry], dict[str, Decimal]]:
+    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
+    items = raw.get("rate_card", raw.get("entries", []))
     fx = {pair: _money(rate) for pair, rate in raw.get("fx_rates", {}).items()}
-    return raw.get("period", ""), entries, fx
+    return _parse_cost_entries(items), fx
+
+
+def load_monthly_platform_costs(data_dir: Path | None = None) -> list[MonthlyPlatformCost]:
+    raw = _read_json((data_dir or default_data_dir()) / "costs.json")
+    return [
+        MonthlyPlatformCost(
+            period=item["period"],
+            platform_cost=_money(item["platform_cost"]),
+            active_members=item["active_members"],
+            gross_revenue=_money(item["gross_revenue"]),
+        )
+        for item in raw.get("monthly_history", [])
+    ]
 
 
 def load_revenue(data_dir: Path | None = None) -> list[RevenueEntry]:
@@ -100,4 +128,8 @@ def load_membership(data_dir: Path | None = None) -> list[MembershipRecord]:
             churned_at=item.get("churned_at"),
         )
         for item in raw["members"]
-    ]
+    ]
+
+
+def latest_period(monthly_costs: list[MonthlyPlatformCost]) -> str:
+    return max(item.period for item in monthly_costs)