Feat: Add ambient types for external libraries

Co-authored-by: gemini-3.7-flash <noreply@google.com>

types.d.ts

@@ -0,0 +1,27 @@
+declare module 'zwus' {
+    export function encodeString(text: string, base: string | number): string;
+    export function decodeToString(text: string, base: string | number): string;
+    export function encodeNumberArray(arr: number[], base: string | number): string;
+    export function decodeToNumberArray(text: string, base: string | number): number[];
+    const zwus: {
+        encodeString: typeof encodeString;
+        decodeToString: typeof decodeToString;
+        encodeNumberArray: typeof encodeNumberArray;
+        decodeToNumberArray: typeof decodeToNumberArray;
+    };
+    export default zwus;
+}
+
+declare module 'generic-speck' {
+    export interface SpeckOptions {
+        bits?: number;
+        rounds?: number;
+        rightRotations?: number;
+        leftRotations?: number;
+    }
+    export interface SpeckInstance {
+        encrypt: (plain: number, key: number[]) => number;
+        decrypt: (cipher: number, key: number[]) => number;
+    }
+    export default function speck(options?: SpeckOptions): SpeckInstance;
+}