Initial scaffold: Nakama backend, Godot client, content schema

Sets up the Step 1 (Project Foundation) and Step 2 (Content Schemas) scaffold
from the implementation sequence. Includes Docker Compose stack, Nakama
TypeScript module stubs, PostgreSQL migration, Godot 4 project shell with
scene stubs and NakamaClient singleton, YAML content schemas for all entity
types, and example data for 3 characters, 2 jobs, and all 7 core resources.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nakama/modules/inventory.ts

@@ -0,0 +1,52 @@
+// inventory.ts — player inventory and resource ledger
+//
+// Every grant and spend must produce a ledger entry so the economy is
+// fully auditable. The wallet tracks numeric resources (gold, wood, etc.).
+// The inventory tracks discrete items and character roster membership.
+
+// Resource IDs — must match the keys used in content/schema/resource.yaml
+export const RESOURCE_IDS = [
+  "gold",
+  "wood",
+  "stone",
+  "knowledge",
+  "experience",
+  "mana",
+  "diamond",
+] as const;
+
+export type ResourceId = typeof RESOURCE_IDS[number];
+
+export function rpcGetInventory(
+  ctx: nkruntime.Context,
+  logger: nkruntime.Logger,
+  nk: nkruntime.Nakama,
+  _payload: string
+): string {
+  // TODO PR 4: read character roster and item inventory from storage
+  logger.info(`inventory/get stub called by ${ctx.userId}`);
+
+  return JSON.stringify({
+    characters: [],
+    items: [],
+    message: "Inventory is stubbed. Implement in PR 4.",
+  });
+}
+
+export function rpcGetResources(
+  ctx: nkruntime.Context,
+  logger: nkruntime.Logger,
+  nk: nkruntime.Nakama,
+  _payload: string
+): string {
+  // Read wallet balances — these are already tracked by Nakama's wallet system
+  const account = nk.accountGetId(ctx.userId);
+  const wallet = account.wallet ?? {};
+
+  const resources: Record<string, number> = {};
+  for (const id of RESOURCE_IDS) {
+    resources[id] = Number(wallet[id] ?? 0);
+  }
+
+  return JSON.stringify({ resources });
+}