feat(growth): B2B segment kapısı + funnel-bucket A/B deneyi (Kova B)

Fix (herkes, flag'siz): evrensel post-auth segment kapısı (segment-gate.tsx).
Kayıtların ~%41'i segmentsizdi çünkü login.tsx Google OAuth segment adımını
atlıyordu. Yeni kullanıcıya zorunlu (açığı kapatır), mevcut segmentsize
7g-cooldown'lu yumuşak prompt (~538 backfill). Segment localStorage +
PostHog person prop (b2b_segment); backend persist faz 2.

Kova B (funnel-bucket flag, b2b_qualified): trial-value-upsell'e segmente-özel
Meta-kanıtlı kopya (iade / yanlış-parça / sınırsız-şase). Flag SADECE banner
görünürken okunur → deney maruziyeti = gerçekten gören aktif trial'lar.
vehicle_owner / bilinmeyen segment → nötr control kopya (ürün kararı).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/web/src/components/auth/segment-gate.tsx

@@ -0,0 +1,145 @@
+import { SegmentQualifier } from "@/components/auth/segment-qualifier";
+import { useAuth } from "@/hooks/use-auth";
+import { capture, setPeopleProperties } from "@/lib/posthog";
+import { Button } from "@sase/ui";
+import { useLocation } from "@tanstack/react-router";
+import { useEffect, useState } from "react";
+
+/**
+ * Universal post-auth segment gate.
+ *
+ * The register page gates segment selection behind the form, but that only
+ * covers email + register-page-OAuth signups. A user who starts Google OAuth
+ * from the LOGIN page (login.tsx) gets an account created server-side and lands
+ * on the dashboard with no segment ever chosen — this is the bulk of the ~41%
+ * of signups with a null segment. Segment isn't persisted server-side (only
+ * localStorage + a PostHog person property), so we enforce it here at the one
+ * chokepoint every authenticated user passes through: the dashboard.
+ *
+ * Behaviour (product decision 2026-07-27):
+ *  - New users (account created in the last few minutes → the login-OAuth gap):
+ *    MANDATORY, non-dismissible modal.
+ *  - Existing segment-less users (the ~538 backfill): SOFT, dismissible with a
+ *    cooldown so we re-ask later without nagging or blocking active/paying users.
+ *
+ * This is a baseline fix shipped to everyone — NOT the `funnel-bucket` A/B
+ * experiment (that gates the tailored value/upgrade experience separately).
+ */
+const SEGMENT_KEY = "sase-b2b-segment";
+const DISMISS_UNTIL_KEY = "sase-b2b-segment-prompt-until";
+// Account younger than this ⇒ treat as a fresh signup (mandatory). Generous so
+// the signup → first dashboard load always counts, even with a slow OAuth hop.
+const NEW_USER_WINDOW_MS = 15 * 60 * 1000;
+// How long a "Daha sonra" dismissal silences the soft prompt for existing users.
+const DISMISS_COOLDOWN_MS = 7 * 24 * 60 * 60 * 1000;
+
+function readSegment(): string | null {
+  try {
+    return localStorage.getItem(SEGMENT_KEY);
+  } catch {
+    return null;
+  }
+}
+
+export function SegmentGate() {
+  const { user, isLoading } = useAuth();
+  const location = useLocation();
+  const [open, setOpen] = useState(false);
+  const [mandatory, setMandatory] = useState(false);
+
+  useEffect(() => {
+    // Only inside the app, only once the session has resolved to a real user.
+    if (isLoading || !user) {
+      setOpen(false);
+      return;
+    }
+    if (!location.pathname.startsWith("/dashboard")) {
+      setOpen(false);
+      return;
+    }
+    // Already segmented — nothing to do. (Register writes this pre-redirect, so
+    // email + register-OAuth signups never see the gate.)
+    if (readSegment()) {
+      setOpen(false);
+      return;
+    }
+
+    const createdAt = user.createdAt ? new Date(user.createdAt).getTime() : 0;
+    const isNew = createdAt > 0 && Date.now() - createdAt < NEW_USER_WINDOW_MS;
+
+    if (isNew) {
+      setMandatory(true);
+      setOpen(true);
+      return;
+    }
+
+    // Existing segment-less user: honour the soft-dismiss cooldown.
+    let dismissedUntil = 0;
+    try {
+      dismissedUntil = Number(localStorage.getItem(DISMISS_UNTIL_KEY)) || 0;
+    } catch {
+      dismissedUntil = 0;
+    }
+    if (Date.now() < dismissedUntil) {
+      setOpen(false);
+      return;
+    }
+    setMandatory(false);
+    setOpen(true);
+  }, [user, isLoading, location.pathname]);
+
+  if (!open) return null;
+
+  function handleSelect(seg: string) {
+    try {
+      localStorage.setItem(SEGMENT_KEY, seg);
+    } catch {
+      // localStorage unavailable — still fire analytics below.
+    }
+    // `source` distinguishes the login-OAuth gap fill from the backfill so we can
+    // measure each in PostHog; mirrors register.tsx's signup_segment_selected.
+    capture("signup_segment_selected", {
+      segment: seg,
+      source: mandatory ? "post_signup_gate" : "backfill_gate",
+    });
+    setPeopleProperties({ b2b_segment: seg });
+    setOpen(false);
+  }
+
+  function handleDismiss() {
+    try {
+      localStorage.setItem(DISMISS_UNTIL_KEY, String(Date.now() + DISMISS_COOLDOWN_MS));
+    } catch {
+      // best-effort
+    }
+    capture("signup_segment_prompt_dismissed");
+    setOpen(false);
+  }
+
+  return (
+    <div
+      className="fixed inset-0 z-[60] flex items-center justify-center overflow-y-auto bg-background/80 p-4 backdrop-blur-sm"
+      // biome-ignore lint/a11y/useSemanticElements: overlay modal — role="dialog"+aria-modal is the correct ARIA here; a native <dialog> would need imperative showModal() plumbing this SPA overlay doesn't use
+      role="dialog"
+      aria-modal="true"
+      aria-label="İşletme türü seçimi"
+    >
+      <div className="my-auto w-full max-w-md rounded-2xl border border-border bg-card p-6 shadow-xl">
+        <div>
+          <h2 className="text-xl font-bold tracking-tight">Bu platform kimler için?</h2>
+          <p className="mt-2 text-sm text-muted-foreground">
+            İşletmeni seç — sana uygun sınırsız şase sorgulama erişimini açalım.
+          </p>
+        </div>
+        <div className="mt-5">
+          <SegmentQualifier onSelect={handleSelect} />
+        </div>
+        {!mandatory && (
+          <Button variant="ghost" className="mt-3 w-full" onClick={handleDismiss}>
+            Daha sonra
+          </Button>
+        )}
+      </div>
+    </div>
+  );
+}

apps/web/src/components/trial-value-upsell.tsx

@@ -1,7 +1,7 @@
 import { api } from "@/lib/api-client";
 import { useSession } from "@/lib/auth-client";
 import { useTranslation } from "@/lib/i18n";
-import { capture } from "@/lib/posthog";
+import { capture, subscribeFeatureFlag } from "@/lib/posthog";
 import { Button } from "@sase/ui";
 import { useQuery } from "@tanstack/react-query";
 import { Link } from "@tanstack/react-router";
@@ -25,6 +25,31 @@ const VALUE_THRESHOLD = 3;
 // Urgency banner owns days <= 3; this one owns days > 3 (no overlap).
 const URGENCY_WINDOW_DAYS = 3;
 
+// Kova B of the `funnel-bucket` A/B experiment: segment-tailored, Meta-proven
+// value copy for the b2b_qualified variant. These hooks are the ones that won on
+// Meta (iade / yanlış-parça / sınırsız-şase framing). Only real B2B segments get
+// the pitch; vehicle_owner / unknown fall back to the neutral control copy
+// (product decision 2026-07-27 — don't push a subscription on consumers).
+const SEGMENT_KEY = "sase-b2b-segment";
+const B2B_COPY: Record<string, { title: string; desc: string }> = {
+  parts_dealer: {
+    title: "Yanlış parça siparişine son",
+    desc: "Dükkânına gelen her araçta şaseden doğru OEM parça — iade ve stok derdi yok.",
+  },
+  wholesaler: {
+    title: "Her siparişte birebir OEM",
+    desc: "Toptan siparişlerde şaseden doğru OEM eşleşmesi — yanlış kalem, iade yok.",
+  },
+  ecommerce: {
+    title: "Listelemende doğru parça",
+    desc: "Şaseden doğru OEM ile hatalı satışı ve iade oranını düşür.",
+  },
+  service_fleet: {
+    title: "Serviste doğru parça, ilk seferde",
+    desc: "Her araçta şaseden doğru OEM — bekleme yok, yanlış sipariş yok.",
+  },
+};
+
 function dismissStorageKey(userId: string | null | undefined, endDate: string): string {
   return `trialValueUpsellDismissed-${userId ?? "anon"}-${endDate}`;
 }
@@ -80,6 +105,26 @@ export function TrialValueUpsell() {
 
   const visible = inWindow && hasProvenValue && !dismissed;
 
+  // Read the experiment flag ONLY once the nudge is visible, so the PostHog
+  // exposure ($feature_flag_called) population = activated trial users who
+  // actually see it — not every dashboard mount. Keeps the thin signal undiluted.
+  const [bucket, setBucket] = useState<string | boolean | undefined>(undefined);
+  useEffect(() => {
+    if (!visible) return;
+    return subscribeFeatureFlag("funnel-bucket", setBucket);
+  }, [visible]);
+  const [segment] = useState<string | null>(() => {
+    try {
+      return localStorage.getItem(SEGMENT_KEY);
+    } catch {
+      return null;
+    }
+  });
+  const tailored =
+    bucket === "b2b_qualified" && segment && segment !== "vehicle_owner"
+      ? B2B_COPY[segment]
+      : undefined;
+
   useEffect(() => {
     if (!visible || viewedRef.current || days === null) return;
     viewedRef.current = true;
@@ -120,16 +165,16 @@ export function TrialValueUpsell() {
       <div className="flex flex-1 flex-col gap-1 sm:flex-row sm:items-center sm:gap-4">
         <div>
           <p className="text-sm font-semibold text-foreground">
-            {t("subscription.valueUpsell.title")}
+            {tailored ? tailored.title : t("subscription.valueUpsell.title")}
           </p>
           <p className="text-xs text-muted-foreground">
-            {t("subscription.valueUpsell.description")}
+            {tailored ? tailored.desc : t("subscription.valueUpsell.description")}
           </p>
         </div>
 
         <Link to="/dashboard/subscription" className="shrink-0" onClick={handleCTAClick}>
           <Button size="sm" className="bg-brand text-white hover:bg-brand/90">
-            {t("subscription.valueUpsell.cta")}
+            {tailored ? "Sınırsız erişime geç" : t("subscription.valueUpsell.cta")}
           </Button>
         </Link>
       </div>