feat: centralized Notion-style taxonomy management in settings

Single persistent option pool per taxonomy (7 fields: offer
categoria/ticket/tipo/obiettivo + catalog fase/offerta/pacchetto),
stored as JSON in the settings table (no DB migration).

- src/lib/taxonomy.ts: pools with lazy seed from in-use values,
  add/remove(cascade)/rename helpers
- Inline creation anywhere registers into the pool (save offer,
  addServiceOption, updateServiceField fase, quickAdd, create macro)
- Deselecting on a row never touches the pool; global delete only
  from settings (cascade-strips tags / nulls columns)
- getOfferFieldOptions + getCatalogFieldOptions read from pools
- Settings: TaxonomyManager (offer + catalog groups), confirm on delete

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

src/lib/offer-queries.ts

@@ -8,7 +8,7 @@ import {
   services,
   tags,
 } from "@/db/schema";
-import { getJsonPool, SETTINGS_KEYS } from "@/lib/settings";
+import { getPool } from "@/lib/taxonomy";
 import type { OfferMacro, OfferMicro, OfferService } from "@/db/schema";
 import { eq, and, asc, inArray, sql } from "drizzle-orm";
 
@@ -273,40 +273,14 @@ export type OfferFieldOptions = {
 };
 
 // Shared option pools for the offer editor's select fields (Notion-style
-// dropdowns). Tipo, Obiettivo, and Categoria are merged from the managed
-// settings pools + any values already in use (retrocompatibility).
+// dropdowns). All four read from the centralized, persistent taxonomy pools
+// (src/lib/taxonomy.ts), seeded from existing values on first access.
 export async function getOfferFieldOptions(): Promise<OfferFieldOptions> {
-  const [categoriaRows, ticketRows, tagRows, tipoPool, obiettivoPool, categoriaPool] =
-    await Promise.all([
-      db.selectDistinct({ value: offer_macros.category }).from(offer_macros),
-      db.selectDistinct({ value: offer_macros.ticket }).from(offer_macros),
-      db
-        .selectDistinct({ name: tags.name, type: tags.entity_type })
-        .from(tags)
-        .where(inArray(tags.entity_type, [OFFER_TIPO_ENTITY, OFFER_OBIETTIVO_ENTITY])),
-      getJsonPool(SETTINGS_KEYS.OFFER_TIPO_POOL),
-      getJsonPool(SETTINGS_KEYS.OFFER_OBIETTIVO_POOL),
-      getJsonPool(SETTINGS_KEYS.OFFER_CATEGORIA_POOL),
-    ]);
-
-  const sortUnique = (arr: (string | null)[]) =>
-    Array.from(new Set(arr.filter((v): v is string => !!v && v.trim().length > 0))).sort(
-      (a, b) => a.localeCompare(b, "it")
-    );
-
-  return {
-    categoria: sortUnique([
-      ...categoriaPool,
-      ...categoriaRows.map((r) => r.value),
-    ]),
-    ticket: sortUnique(ticketRows.map((r) => r.value)),
-    tipo: sortUnique([
-      ...tipoPool,
-      ...tagRows.filter((r) => r.type === OFFER_TIPO_ENTITY).map((r) => r.name),
-    ]),
-    obiettivo: sortUnique([
-      ...obiettivoPool,
-      ...tagRows.filter((r) => r.type === OFFER_OBIETTIVO_ENTITY).map((r) => r.name),
-    ]),
-  };
+  const [categoria, ticket, tipo, obiettivo] = await Promise.all([
+    getPool("offer_categoria"),
+    getPool("offer_ticket"),
+    getPool("offer_tipo"),
+    getPool("offer_obiettivo"),
+  ]);
+  return { categoria, ticket, tipo, obiettivo };
 }