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/app/admin/catalog/actions.ts

@@ -7,6 +7,7 @@ import { eq, and } from "drizzle-orm";
 import { z } from "zod";
 import { getServerSession } from "next-auth";
 import { authOptions } from "@/lib/auth";
+import { addPoolValue, renamePoolValue } from "@/lib/taxonomy";
 
 const serviceSchema = z.object({
   name: z.string().min(1, "Nome richiesto"),
@@ -95,6 +96,7 @@ export async function updateServiceField(
   } else if (fieldName === "fase") {
     const s = String(value).trim();
     await db.update(services).set({ fase: s || null }).where(eq(services.id, serviceId));
+    if (s) await addPoolValue("service_fase", s);
   } else if (fieldName === "unit_price") {
     // Normalize locale-formatted input (WR-04): the cell displays it-IT (€1.234,50),
     // so an admin may type "1.234,50". When a comma is present, treat "." as thousands
@@ -143,6 +145,9 @@ export async function addServiceOption(
     .values({ entity_type: MULTI_ENTITY[field], entity_id: serviceId, name: trimmed })
     .onConflictDoNothing();
 
+  // Register into the persistent pool so it survives unassignment / shows in settings.
+  await addPoolValue(field === "tag" ? "service_offerta" : "service_pacchetto", trimmed);
+
   revalidatePath("/admin/catalog");
 }
 
@@ -187,10 +192,12 @@ export async function renameServiceOption(
       .update(tags)
       .set({ name: next })
       .where(and(eq(tags.entity_type, MULTI_ENTITY[field]), eq(tags.name, oldValue)));
+    await renamePoolValue(field === "tag" ? "service_offerta" : "service_pacchetto", oldValue, next);
   } else if (field === "categoria") {
     await db.update(services).set({ category: next }).where(eq(services.category, oldValue));
   } else if (field === "fase") {
     await db.update(services).set({ fase: next }).where(eq(services.fase, oldValue));
+    await renamePoolValue("service_fase", oldValue, next);
   } else {
     throw new Error(`Campo non valido: ${field}`);
   }
@@ -227,14 +234,16 @@ export async function quickAddService(payload: QuickAddPayload | string) {
     unit_price = num.toFixed(2);
   }
 
+  const fase = data.fase?.trim() || null;
   await db.insert(services).values({
     name,
     description: data.description?.trim() || null,
     category: data.category?.trim() || null,
-    fase: data.fase?.trim() || null,
+    fase,
     unit_price,
     active: true,
   });
+  if (fase) await addPoolValue("service_fase", fase);
 
   revalidatePath("/admin/catalog");
 }