test(profile): cover the third gender value where it used to be lost

Adds the cases that were missing everywhere except the FHIR conformance
suite: an empty string clears without taking its siblings down, OTHER
round-trips through the profile and onboarding writes, an unsupported
value is still refused and says which field it is about, the Strain
model scores an unanswered account on neither side, the dashboard bands
give OTHER the neutral fallback, the snapshot payload carries the value
instead of flattening it, and the doctor-report cover omits the row
rather than claiming a value the account never chose.

Refs #645

src/app/api/insights/generate/route.ts

@@ -68,6 +68,7 @@ import { apiHandler, requireAuth } from "@/lib/api-handler";
 import { requireAssistantSurface } from "@/lib/feature-flags";
 import { invalidateUserInsights } from "@/lib/cache/invalidate";
 import { annotate } from "@/lib/logging/context";
+import { toProfileSex } from "@/lib/profile/sex";
 import { resolveServerLocale } from "@/lib/i18n/server-locale";
 import { normalizeLocale } from "@/lib/insights/status-shared";
 import { hasUsableStatusProvider } from "@/lib/insights/status-provider";
@@ -597,10 +598,7 @@ export const POST = apiHandler((request: NextRequest) =>
     // v1.10.0 — fold a notable derived wellness signal (readiness / recovery
     // shift, confidence-gated) into the briefing as a SYSTEM CONTEXT block.
     // Reads the one derived contract; null (the common case) costs nothing.
-    const derivedSex =
-      dbUser?.gender === "MALE" || dbUser?.gender === "FEMALE"
-        ? (dbUser.gender as "MALE" | "FEMALE")
-        : null;
+    const derivedSex = toProfileSex(dbUser?.gender);
     const derivedBriefing = await detectDerivedBriefingSignals(userId, {
       ageYears: getAgeFromDateOfBirth(dbUser?.dateOfBirth ?? null),
       sex: derivedSex,