feat(earnings): add Earnings Center packets (9308-9310 / 9407-9408)

Client-side counterpart to the emulator earnings contract
(emulatore/docs/earnings-packet-contract.md). Outgoing: RequestEarningsCenter /
ClaimEarningsReward(categoryKey) / ClaimAllEarningsRewards. Incoming:
EarningsCenter + EarningsClaimResult sharing one entry/reward shape. Registered
in NitroMessages + barrel chain (incoming/outgoing/parser).

packages/communication/src/messages/parser/earnings/EarningsCenterParser.ts

@@ -0,0 +1,68 @@
+import { IMessageDataWrapper, IMessageParser } from '@nitrots/api';
+
+export interface IEarningsReward
+{
+    type: string;       // credits | pixels | points | badge | item | hc_days
+    amount: number;
+    pointsType: number; // currency type when type === 'points'
+    data: string;       // badge code (badge), items_base.id (item), else ''
+}
+
+export interface IEarningsEntry
+{
+    categoryKey: string;
+    enabled: boolean;
+    claimable: boolean;
+    nextClaimAt: number;
+    rewards: IEarningsReward[];
+}
+
+// Shared entry reader — the claim-result parser embeds the same shape.
+export function readEarningsEntry(wrapper: IMessageDataWrapper): IEarningsEntry
+{
+    const categoryKey = wrapper.readString();
+    const enabled = wrapper.readBoolean();
+    const claimable = wrapper.readBoolean();
+    const nextClaimAt = wrapper.readInt();
+
+    const rewardCount = wrapper.readInt();
+    const rewards: IEarningsReward[] = [];
+
+    for(let i = 0; i < rewardCount; i++)
+    {
+        rewards.push({
+            type: wrapper.readString(),
+            amount: wrapper.readInt(),
+            pointsType: wrapper.readInt(),
+            data: wrapper.readString()
+        });
+    }
+
+    return { categoryKey, enabled, claimable, nextClaimAt, rewards };
+}
+
+export class EarningsCenterParser implements IMessageParser
+{
+    private _entries: IEarningsEntry[] = [];
+
+    public flush(): boolean
+    {
+        this._entries = [];
+
+        return true;
+    }
+
+    public parse(wrapper: IMessageDataWrapper): boolean
+    {
+        if(!wrapper) return false;
+
+        const count = wrapper.readInt();
+        this._entries = [];
+
+        for(let i = 0; i < count; i++) this._entries.push(readEarningsEntry(wrapper));
+
+        return true;
+    }
+
+    public get entries(): IEarningsEntry[] { return this._entries; }
+}