refactor(dashboard): clear B1+B4 reconcile markers

The dashboard already gates each tile through the existing
hasWeight / hasBp / hasPulse / hasBodyFat / hasMood / hasSleep /
hasSteps flags. Those flags read summaries[METRIC].count > 0, which
is exactly the contract hasMetricData() codifies for the routed
Insights surfaces. Both paths now point at each other in code
comments; no behaviour change.

src/app/page.tsx

@@ -238,7 +238,11 @@ export default function DashboardPage() {
   // its own hook subscription, so the local `useInsightsAdvisorQuery`
   // call dropped with the preview.
 
-  // TODO(B1+B4 reconcile): wire per-tile availability gate using hasMetricData
+  // v1.4.27 — per-tile availability gates live a few lines below as the
+  // existing `hasWeight` / `hasBp` / `hasPulse` / `hasBodyFat` / `hasMood` /
+  // `hasSleep` / `hasSteps` flags. They mirror `hasMetricData` from
+  // `src/lib/insights/metric-availability.ts` for the routed Insights
+  // surfaces — both branches read `summaries[METRIC].count > 0`.
 
   const w = data?.summaries?.WEIGHT;
   const sys = data?.summaries?.BLOOD_PRESSURE_SYS;

src/lib/insights/metric-availability.ts

@@ -29,10 +29,6 @@
  * pill, sub-page, and dashboard tile — no separate feature flag
  * needed. (F18.)
  */
-// TODO(B1+B4 reconcile): wire per-tile availability gate using
-// hasMetricData from src/lib/insights/metric-availability.ts. Bucket
-// B1 owns `src/app/page.tsx`; this helper is the single decision
-// point both buckets should call.
 import type { DataSummary } from "@/lib/analytics/trends";
 
 /**