feat(web): reinforce value on subscription plan selection

Three CRO additions at the point of decision:
- Outcome-focused page subtitle ("Doğru parçayı saniyede bul …") replacing
  the purely procedural copy.
- Per-day price anchor on every plan card (≈ ₺X/gün), reframing the cost as
  a small daily number. Computed from the displayed monthly/yearly price.
- "2 ay bedava" note under the billing toggle when yearly is selected,
  making the otherwise-abstract -17% concrete (yearly = 10× monthly).

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

apps/web/src/messages/en.json

@@ -123,10 +123,12 @@
   },
   "subscription": {
     "title": "Subscription",
-    "subtitle": "Pick a plan, choose your brands, complete payment — all on one page.",
+    "subtitle": "Find the right part in seconds — pick a plan and start searching.",
     "step": "Step",
     "selected": "Selected",
     "tapToSelect": "Select",
+    "perDay": "≈ {amount}/day",
+    "yearlyFreeMonths": "2 months free with yearly billing",
     "selectExactBrands": "Please select exactly {count} brands.",
     "steps": {
       "plan": {

apps/web/src/messages/tr.json

@@ -123,10 +123,12 @@
   },
   "subscription": {
     "title": "Abonelik",
-    "subtitle": "Planını seç, markalarını belirle, ödemeni yap. Hepsi tek sayfada.",
+    "subtitle": "Doğru parçayı saniyede bul — planını seç, hemen aramaya başla.",
     "step": "Adım",
     "selected": "Seçildi",
     "tapToSelect": "Seç",
+    "perDay": "≈ {amount}/gün",
+    "yearlyFreeMonths": "Yıllık ödemede 2 ay bedava",
     "selectExactBrands": "Lütfen tam olarak {count} marka seçin.",
     "steps": {
       "plan": {