feat(canonical): şablon ENTRY-seviyesi — decode anında tam gezinilebilir yapı

Kullanıcının orijinal tasarımı: aynı (kaynak, marka)da kategori yapısı birebir
aynı — değişen yalnız parça kodları/şemalar. Önceki şablon sadece kova/alt-yaprak
BAŞLIKLARINI overlay ediyordu → taze araçta "Aydınlatma — 0 kategori". Yeni:
canonical_template_entries (migration 0031) — markanın paylaşılan kaynak-kategori
ADLARI (≥2 araç); backfill'de rebuild. overlayTemplate eksik adları disabled
placeholder olarak basar (unavailable=true, CategoryGrid zaten soluk+tıklanamaz
render ediyor) → decode anında her kova tam adlarıyla dolu; drill tamamlanınca
placeholder'lar gerçek satıra dönüşür.

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

apps/api/src/database/schema/core.ts

@@ -1017,6 +1017,25 @@ export const categoryCanonicalMap = pgTable(
 // brand template so the user sees the FULL canonical structure instantly, before
 // this vehicle's own tree is deep-drilled by the prefetch backfill. Rebuilt at
 // the end of each global canonical-backfill run (derived, so full-refresh).
+// Entry-level companion of canonicalStructureTemplate: the browsable source-
+// category NAMES every vehicle of (source, brand) shares under a bucket/sub.
+// A freshly-decoded vehicle renders these immediately (placeholder until its
+// own row exists) — only parts/schemas are vehicle-specific.
+export const canonicalTemplateEntries = pgTable(
+  "canonical_template_entries",
+  {
+    id: uuid("id").primaryKey().defaultRandom(),
+    source: varchar("source", { length: 20 }).notNull(),
+    brand: varchar("brand", { length: 120 }).notNull(),
+    canonicalCategoryId: uuid("canonical_category_id").notNull(),
+    canonicalSubcategoryId: uuid("canonical_subcategory_id"),
+    name: varchar("name", { length: 500 }).notNull(),
+    vehicleCount: integer("vehicle_count").default(0).notNull(),
+    updatedAt: timestamp("updated_at", { withTimezone: true }).defaultNow().notNull(),
+  },
+  (table) => [index("canonical_template_entries_sb_idx").on(table.source, table.brand)],
+);
+
 export const canonicalStructureTemplate = pgTable(
   "canonical_structure_template",
   {