fix(account): answer profile writes with the derived birth-time truth

A zero-uncertainty exact declaration is accepted server-side as the active
minute, but the account write only answered {ok:true}. Every save path then
kept the draft it submitted, so the first consultation after initialization
asked for unverified_birth_time against an accepted profile and was rejected
with mode_changed before billing.

The account route now returns the status and active minute it derived, and
every profile save adopts that result instead of its own local guess.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/lib/account-profile-patch.ts

@@ -304,3 +304,30 @@ export function resolveAccountBirthTimeApplicationPatch(
     rectification_case_id: null,
   };
 }
+
+export type AppliedAccountBirthTime = Readonly<{
+  status: string | null;
+  activeTime: string | null;
+}>;
+
+/**
+ * The birth-time truth the account owns after a successful write. Status and
+ * active minute are derived server-side, so a caller that keeps the declaration
+ * it submitted would consult under a mode the server no longer accepts.
+ */
+export function resolveAppliedAccountBirthTime(
+  current: AccountBirthTimeState | null,
+  applicationPatch: AccountBirthTimeApplicationPatch,
+): AppliedAccountBirthTime {
+  const activeTime = normalizeApplicableBirthClock(
+    applicationPatch.active_birth_time !== undefined
+      ? applicationPatch.active_birth_time
+      : current?.active_birth_time ?? current?.birth_time,
+  );
+  return Object.freeze({
+    status: applicationPatch.birth_time_status
+      ?? current?.birth_time_status
+      ?? (activeTime ? "confirmed" : null),
+    activeTime,
+  });
+}

frontend/src/lib/birth-time-intake-model.ts

@@ -326,6 +326,31 @@ export function birthTimePersistenceValues(draft: BirthTimeDraft) {
   };
 }
 
+const persistedBirthTimeStatuses = [
+  "reported", "assessing", "rectifying", "candidate", "accepted", "confirmed",
+] as const satisfies readonly Exclude<BirthTimeStatus, "">[];
+
+/**
+ * Reconciles a submitted declaration with the birth-time truth the account write
+ * returned. The server decides whether a declaration is already usable as the
+ * active minute, so consultation mode must never be derived from the draft alone.
+ */
+export function applyPersistedBirthTime<T extends BirthTimeDraft>(
+  draft: T,
+  applied: unknown,
+): T {
+  if (applied === null || typeof applied !== "object") return draft;
+  const { status, activeTime } = applied as { status?: unknown; activeTime?: unknown };
+  const persistedStatus = persistedBirthTimeStatuses.find((candidate) => candidate === status);
+  if (!persistedStatus) return draft;
+  const clock = typeof activeTime === "string" ? activeTime.slice(0, 5) : "";
+  return {
+    ...draft,
+    time: isBirthClockTime(clock) ? clock : "",
+    birthTimeStatus: persistedStatus,
+  };
+}
+
 export function describeBirthTimeDraft(draft: BirthTimeDraft) {
   const [year, month, day] = draft.date.split("-").map(Number);
   const date = `${year}年${month}月${day}日`;