feat(web): align pricing cards with subscription page

Bring the public pricing cards in line with the in-app subscription page and
strengthen the CTA:
- Move the "Popüler" badge from 2 Marka to Full Paket (one consistent story
  across both surfaces).
- CTA "Başla" -> "Ücretsiz Başla" (leans on the free trial the flow grants).
- Yearly line now uses a consistent ₺ format ("veya ₺2.000,00/yıl") plus a
  "· 2 ay bedava" savings cue instead of the bare, differently-formatted
  "veya 2.000,00 TL/yıl".
- Plan-decision helper above the grid ("Hangi planı seçmeliyim? …").

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/routes/__tests__/pricing-plans.test.tsx

@@ -0,0 +1,21 @@
+/**
+ * Guards that the public pricing page emphasises the same plan as the in-app
+ * subscription page. The "Popüler" badge was moved from 2 Marka to Full Paket
+ * so both surfaces tell one story.
+ */
+
+import { describe, expect, test } from "vitest";
+
+import { plans } from "@/routes/pricing";
+
+describe("pricing plans", () => {
+  test("Full Paket is the only popular plan (aligned with subscription)", () => {
+    expect(plans.find((p) => p.key === "full")?.popular).toBe(true);
+    expect(plans.find((p) => p.key === "brand2")?.popular).toBeFalsy();
+    expect(plans.filter((p) => p.popular).map((p) => p.key)).toEqual(["full"]);
+  });
+
+  test("still lists all four tiers in ascending brand order", () => {
+    expect(plans.map((p) => p.key)).toEqual(["brand1", "brand2", "brand3", "full"]);
+  });
+});