pack: economy MVP -- Numismatics + Patchouli + welcome flow, bump to 0.18.0

Adds the currency layer and the first-join experience.

Mods:
- Create: Numismatics 1.0.20  (currency, vendor blocks, piggy banks)
- Patchouli 1.21.1-93         (kept in pack for future rich manual book)

KubeJS scripts (server_scripts/):
- economy_policy.js  remove ALL Waystones recipes; remove coin recipes
                     only (piggy banks etc. stay craftable for now)
- welcome.js         first-login grant: 1 waystone + vanilla written-book
                     "Brass & Sigil Manual v1" (5 pages: welcome,
                     waystones, money, spawn plots, rules). Per-player
                     flag bnsWelcomeGranted in persistentData gates it.

KubeJS scripts (client_scripts/):
- jei_hides.js       hide all Waystones items + 4 coin denominations from
                     the JEI ingredient list. Combined with the recipe
                     removal players never encounter these items via
                     normal play -- only via the welcome grant or the
                     bank exchange.

The written-book manual is the MVP placeholder. When more content lands
(plot system, dynamic exchange, etc.) it'll be replaced by a proper
Patchouli book authored as a tweak jar -- Patchouli's already in the
lockfile so no mod-add will be needed at that point.

pack/overrides/kubejs/server_scripts/economy_policy.js

@@ -0,0 +1,24 @@
+// Brass & Sigil — economy policy (recipe removal)
+//
+// Players can't craft Waystones items (they're distributed by the welcome
+// grant -- see welcome.js -- and any replacements come from the bank
+// vendor in the future). Players also can't manufacture currency: coins
+// only enter circulation through the bank exchange (item-in / coin-out).
+//
+// Other Numismatics blocks (piggy banks, bank tellers, vendor blocks) stay
+// craftable -- those are infrastructure, not currency.
+
+ServerEvents.recipes(event => {
+    // Block ALL crafting of Waystones items. The welcome-grant script
+    // gives each new player exactly one regular waystone; any further
+    // recovery happens via OP /give or future bank vendor.
+    event.remove({ mod: 'waystones' });
+
+    // Block coin manufacturing only -- 4 denominations.
+    [
+        'numismatics:spur',
+        'numismatics:bevel',
+        'numismatics:sundial',
+        'numismatics:sun',
+    ].forEach(coin => event.remove({ output: coin }));
+});