feat: implement dashboard state management, API proxy layer, and modular UI components for weather monitoring and payments

frontend/lib/api-proxy.ts

@@ -1,4 +1,10 @@
+import type { NextRequest } from "next/server";
 import { NextResponse } from "next/server";
+import {
+  applyAuthResponseCookies,
+  buildBackendRequestHeaders,
+} from "@/lib/backend-auth";
+import { buildCachedJsonResponse } from "@/lib/http-cache";
 
 const PASSTHROUGH_UPSTREAM_STATUSES = new Set([
   400,
@@ -70,3 +76,64 @@ export function buildProxyExceptionResponse(
 
   return NextResponse.json(body, { status: options.status ?? 500 });
 }
+
+export async function proxyBackendJsonGet(
+  req: NextRequest,
+  options: {
+    cacheControl?: string;
+    conditionalResponse?: boolean;
+    detailLimit?: number;
+    error?: string;
+    fetchCache?: RequestCache;
+    includeSupabaseIdentity?: boolean;
+    publicMessage: string;
+    revalidateSeconds?: number;
+    signal?: AbortSignal;
+    statusOnException?: number;
+    timeoutPublicMessage?: string;
+    url: string;
+  },
+) {
+  let auth: Awaited<ReturnType<typeof buildBackendRequestHeaders>> | null = null;
+  try {
+    auth = await buildBackendRequestHeaders(req, {
+      includeSupabaseIdentity: options.includeSupabaseIdentity ?? false,
+    });
+    const res = await fetch(options.url, {
+      headers: auth.headers,
+      ...(options.fetchCache
+        ? { cache: options.fetchCache }
+        : { next: { revalidate: options.revalidateSeconds ?? 30 } }),
+      signal: options.signal,
+    });
+    if (!res.ok) {
+      const raw = await res.text();
+      const response = buildUpstreamErrorResponse(res.status, raw, {
+        detailLimit: options.detailLimit,
+        error: options.error,
+      });
+      return applyAuthResponseCookies(response, auth.response);
+    }
+
+    const data = await res.json();
+    const response =
+      options.cacheControl && options.conditionalResponse !== false
+        ? buildCachedJsonResponse(req, data, options.cacheControl)
+        : NextResponse.json(data, {
+            headers: options.cacheControl
+              ? { "Cache-Control": options.cacheControl }
+              : undefined,
+          });
+    return applyAuthResponseCookies(response, auth.response);
+  } catch (error) {
+    const timedOut = options.signal?.aborted === true;
+    const response = buildProxyExceptionResponse(error, {
+      publicMessage:
+        timedOut && options.timeoutPublicMessage
+          ? options.timeoutPublicMessage
+          : options.publicMessage,
+      status: timedOut ? 504 : options.statusOnException,
+    });
+    return auth ? applyAuthResponseCookies(response, auth.response) : response;
+  }
+}