feat: add birth rectification preview card

frontend/src/app/api/birth-rectification/route.ts

@@ -0,0 +1,71 @@
+import { NextResponse } from "next/server";
+import { chinaLocations } from "@/data/china-locations";
+
+type Profile = {
+  date?: string;
+  time?: string;
+  provinceCode?: string;
+  cityCode?: string;
+  districtCode?: string;
+};
+
+const jyotishApiBase = process.env.JYOTISH_API_BASE ?? "http://127.0.0.1:5200";
+
+function payloadFromProfile(profile: Profile) {
+  if (!profile.date || !profile.time) return null;
+  const province = chinaLocations.country.provinces.find((item) => item.code === profile.provinceCode);
+  const city = province?.cities.find((item) => item.code === profile.cityCode);
+  const district = city?.districts.find((item) => item.code === profile.districtCode);
+  const location = district ?? city;
+  if (!location) return null;
+  return {
+    birth_time: `${profile.date} ${profile.time}`,
+    uncertainty_minutes: 30,
+    step_minutes: 2,
+    lat: location.center[1],
+    lon: location.center[0],
+    tz: chinaLocations.country.timezone,
+  };
+}
+
+async function fetchQuestionnaire(payload: Record<string, unknown>) {
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), 2500);
+  try {
+    const response = await fetch(`${jyotishApiBase}/api/active_rectification_questions`, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify(payload),
+      cache: "no-store",
+      signal: controller.signal,
+    });
+    if (!response.ok) throw new Error(`jyotish_api_${response.status}`);
+    return await response.json() as Record<string, unknown>;
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+export async function POST(request: Request) {
+  const body = await request.json().catch(() => null) as { profile?: Profile } | null;
+  const payload = payloadFromProfile(body?.profile ?? {});
+  if (!payload) {
+    return NextResponse.json({
+      status: "blocked",
+      boundary: "not_auto_rectified",
+      reason: "profile_incomplete",
+    });
+  }
+  const questionnaire = await fetchQuestionnaire(payload).catch(() => null);
+  const candidateScan = questionnaire?.candidate_scan && typeof questionnaire.candidate_scan === "object"
+    ? questionnaire.candidate_scan
+    : null;
+  const questions = Array.isArray(questionnaire?.questions) ? questionnaire.questions : [];
+  return NextResponse.json({
+    status: questionnaire ? "ok" : "blocked",
+    candidate_scan: candidateScan,
+    question_count: questions.length,
+    boundary: "not_auto_rectified",
+    source: questionnaire ? "active_rectification_questions" : "fallback_unavailable",
+  });
+}