fix(plans): source headline SAP/EPC from baseline for new properties

The plans page computed the plan uplift as postSapPoints - currentSapPoints,
but current_sap_points is unwritten on the property row for new-approach
properties (null -> 0), so the uplift showed the full post score (e.g. +71.39)
and no current rating.

property-meta now backfills currentSapPoints / currentEpcRating from
property_baseline_performance (lodged_sap_score / lodged_epc_band) for
new-approach properties, fixing every propertyMeta consumer (plans page, hero
cards, building passport). e.g. 709634: current 60 (D), uplift now +11.39.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/api/property-meta/[propertyId]/route.ts

@@ -1,7 +1,10 @@
 import { db } from "@/app/db/db";
 import { property } from "@/app/db/schema/property";
 import { serializeBigInt } from "@/app/utils";
-import { resolveDetailsEpcMeta } from "@/lib/services/epcSources";
+import {
+  resolveDetailsEpcMeta,
+  resolvePropertyHeadline,
+} from "@/lib/services/epcSources";
 import { eq } from "drizzle-orm";
 import { NextRequest, NextResponse } from "next/server";
 
@@ -38,15 +41,26 @@ export async function GET(request: NextRequest, props: { params: Promise<{ prope
     return new NextResponse(null, { status: 404 });
   }
 
-  // `detailsEpc` is resolved via the cutoff: legacy properties read
-  // property_details_epc; new-approach ones read epc_property +
-  // property_baseline_performance. See src/lib/services/epcSources.ts.
-  const detailsEpc = await resolveDetailsEpcMeta(
-    propertyMeta.id,
-    propertyMeta.updatedAt,
-  );
+  // `detailsEpc` and the headline SAP/EPC are resolved via the cutoff: legacy
+  // properties read property_details_epc / the property row; new-approach ones
+  // read property_baseline_performance (the property-row headline columns aren't
+  // written yet). See src/lib/services/epcSources.ts.
+  const [detailsEpc, headline] = await Promise.all([
+    resolveDetailsEpcMeta(propertyMeta.id, propertyMeta.updatedAt),
+    resolvePropertyHeadline(propertyMeta.id, propertyMeta.updatedAt),
+  ]);
 
   return new NextResponse(
-    JSON.stringify({ ...propertyMeta, detailsEpc }, serializeBigInt),
+    JSON.stringify(
+      {
+        ...propertyMeta,
+        currentSapPoints:
+          headline.currentSapPoints ?? propertyMeta.currentSapPoints,
+        currentEpcRating:
+          headline.currentEpcRating ?? propertyMeta.currentEpcRating,
+        detailsEpc,
+      },
+      serializeBigInt,
+    ),
   );
 }

src/lib/services/epcSources.ts

@@ -381,6 +381,32 @@ export async function resolveConditionReport(
   return legacyConditionReport((legacy ?? {}) as Record<string, unknown>);
 }
 
+/**
+ * Headline SAP score + EPC band for the property meta. New-approach properties
+ * don't have `current_sap_points` / `current_epc_rating` written on the row yet,
+ * so we fall back to the lodged baseline (property_baseline_performance). Returns
+ * nulls for legacy properties, signalling the caller to keep the row values.
+ *
+ * Uses lodged_* (gov-registry actual) to match the rest of the EPC reads; swap to
+ * effective_* for the modelling-adjusted baseline.
+ */
+export async function resolvePropertyHeadline(
+  propertyId: bigint,
+  updatedAt: Date | string | null | undefined,
+): Promise<{ currentSapPoints: number | null; currentEpcRating: string | null }> {
+  if (!isNewApproach(updatedAt)) {
+    return { currentSapPoints: null, currentEpcRating: null };
+  }
+  const baseline = await db.query.propertyBaselinePerformance.findFirst({
+    columns: { lodgedSapScore: true, lodgedEpcBand: true },
+    where: eq(propertyBaselinePerformance.propertyId, propertyId),
+  });
+  return {
+    currentSapPoints: baseline?.lodgedSapScore ?? null,
+    currentEpcRating: baseline?.lodgedEpcBand ?? null,
+  };
+}
+
 /** The minimal EPC meta the `/api/property-meta` route embeds as `detailsEpc`. */
 export interface DetailsEpcMeta {
   currentEnergyDemand: number | null;