fix(reporting): handle string timestamp from raw db.execute in scenarios

getReportingScenarios uses raw db.execute, which returns created_at as a
string (Drizzle .select() returns a Date). Calling .toISOString() on it
threw 'created_at.toISOString is not a function' and 500'd
/portfolio/[id]/reporting.

Extracted the row→ReportingScenario mapping into a pure, tested module
(reportingScenarios.ts, toReportingScenario) that normalises created_at
whether it arrives as a string or a Date, and covers the modelled-status
and bigint-id / null-name cases. databaseFunctions re-exports the type.

TDD: 4 tests; full suite 446 green, tsc clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/app/portfolio/[slug]/(portfolio)/reporting/databaseFunctions.ts

@@ -24,6 +24,12 @@ import type {
   BaselineMetrics,
   TotalMetrics,
 } from "./types";
+import {
+  toReportingScenario,
+  type ReportingScenario,
+} from "./reportingScenarios";
+
+export type { ReportingScenario };
 
 export async function getPortfolioCounts(portfolioId: number): Promise<number> {
   const result = await db.execute<{ total: number }>(sql`
@@ -239,17 +245,6 @@ export async function loadBaselineMetrics(
   };
 }
 
-export interface ReportingScenario {
-  id: number;
-  name: string;
-  goal: string;
-  goalValue: string | null;
-  budget: number | null;
-  housingType: string;
-  createdAt: string;
-  status: "modelled" | "awaiting_modelling";
-}
-
 /**
  * Scenarios for the reporting combobox: config plus derived modelled state
  * (ADR-0003). Deliberately lighter than listScenariosWithStatus — it derives
@@ -271,7 +266,7 @@ export async function getReportingScenarios(
       goal_value: string | null;
       budget: number | null;
       housing_type: string;
-      created_at: Date;
+      created_at: string | Date;
     }>(sql`
       SELECT id, name, goal, goal_value, budget, housing_type, created_at
       FROM scenario
@@ -287,16 +282,7 @@ export async function getReportingScenarios(
 
   const modelled = new Set(modelledRes.rows.map((r) => String(r.scenario_id)));
 
-  return configRes.rows.map((s) => ({
-    id: Number(s.id),
-    name: s.name ?? `Scenario ${s.id}`,
-    goal: s.goal,
-    goalValue: s.goal_value,
-    budget: s.budget,
-    housingType: s.housing_type,
-    createdAt: s.created_at.toISOString(),
-    status: modelled.has(String(s.id)) ? "modelled" : "awaiting_modelling",
-  }));
+  return configRes.rows.map((s) => toReportingScenario(s, modelled));
 }
 
 /** The portfolio's own goal — drives the current-stock goal callout. */

src/app/portfolio/[slug]/(portfolio)/reporting/reportingScenarios.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from "vitest";
+import { toReportingScenario } from "./reportingScenarios";
+
+describe("toReportingScenario", () => {
+  const baseRow = {
+    id: "12",
+    name: "EPC C by 2030",
+    goal: "Increasing EPC",
+    goal_value: "C",
+    budget: 15000,
+    housing_type: "Social",
+    created_at: "2026-07-04T09:10:00.000Z",
+  };
+
+  it("normalises a string timestamp from raw db.execute to an ISO string", () => {
+    // Regression: raw db.execute returns created_at as a string, so calling
+    // .toISOString() on it threw. The mapper must accept a string.
+    const s = toReportingScenario(baseRow, new Set(["12"]));
+    expect(s.createdAt).toBe("2026-07-04T09:10:00.000Z");
+  });
+
+  it("also accepts a Date timestamp", () => {
+    const s = toReportingScenario(
+      { ...baseRow, created_at: new Date("2026-07-04T09:10:00.000Z") },
+      new Set(),
+    );
+    expect(s.createdAt).toBe("2026-07-04T09:10:00.000Z");
+  });
+
+  it("marks a scenario modelled only when its id is in the modelled set", () => {
+    expect(toReportingScenario(baseRow, new Set(["12"])).status).toBe(
+      "modelled",
+    );
+    expect(toReportingScenario(baseRow, new Set(["99"])).status).toBe(
+      "awaiting_modelling",
+    );
+  });
+
+  it("falls back to a placeholder name and coerces a bigint id", () => {
+    const s = toReportingScenario(
+      { ...baseRow, id: 12n as unknown as bigint, name: null },
+      new Set(["12"]),
+    );
+    expect(s.id).toBe(12);
+    expect(s.name).toBe("Scenario 12");
+    expect(s.status).toBe("modelled");
+  });
+});

src/app/portfolio/[slug]/(portfolio)/reporting/reportingScenarios.ts

@@ -0,0 +1,47 @@
+/**
+ * Pure mapping for the reporting scenario combobox. Lives apart from the db
+ * function so the row-shaping (including the string|Date timestamp quirk of
+ * raw db.execute) is unit-tested without a database.
+ */
+
+export interface ReportingScenario {
+  id: number;
+  name: string;
+  goal: string;
+  goalValue: string | null;
+  budget: number | null;
+  housingType: string;
+  createdAt: string;
+  status: "modelled" | "awaiting_modelling";
+}
+
+export interface RawScenarioRow {
+  id: string | number | bigint;
+  name: string | null;
+  goal: string;
+  goal_value: string | null;
+  budget: number | null;
+  housing_type: string;
+  created_at: string | Date;
+}
+
+/** Raw db.execute returns created_at as a string; Drizzle .select() as a Date. */
+function toIso(value: string | Date): string {
+  return value instanceof Date ? value.toISOString() : value;
+}
+
+export function toReportingScenario(
+  row: RawScenarioRow,
+  modelledIds: Set<string>,
+): ReportingScenario {
+  return {
+    id: Number(row.id),
+    name: row.name ?? `Scenario ${row.id}`,
+    goal: row.goal,
+    goalValue: row.goal_value,
+    budget: row.budget,
+    housingType: row.housing_type,
+    createdAt: toIso(row.created_at),
+    status: modelledIds.has(String(row.id)) ? "modelled" : "awaiting_modelling",
+  };
+}