feat: initialize markr nostr bookmark client

- Add project structure with TypeScript, React, and Vite
- Implement nostr authentication using browser extension (NIP-07)
- Add NIP-51 compliant bookmark fetching and display
- Create minimal UI with login and bookmark components
- Integrate applesauce-core and applesauce-react libraries
- Add responsive styling with dark/light mode support
- Include comprehensive README with setup instructions

This is a minimal MVP for a nostr bookmark client that allows users to
view their bookmarks according to NIP-51 specification.

node_modules/@humanwhocodes/object-schema/src/validation-strategy.js

@@ -0,0 +1,102 @@
+/**
+ * @filedescription Validation Strategy
+ */
+
+"use strict";
+
+//-----------------------------------------------------------------------------
+// Class
+//-----------------------------------------------------------------------------
+
+/**
+ * Container class for several different validation strategies.
+ */
+class ValidationStrategy {
+
+    /**
+     * Validates that a value is an array.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static array(value) {
+        if (!Array.isArray(value)) {
+            throw new TypeError("Expected an array.");
+        }
+    }
+
+    /**
+     * Validates that a value is a boolean.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static boolean(value) {
+        if (typeof value !== "boolean") {
+            throw new TypeError("Expected a Boolean.");
+        }
+    }
+
+    /**
+     * Validates that a value is a number.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static number(value) {
+        if (typeof value !== "number") {
+            throw new TypeError("Expected a number.");
+        }
+    }
+
+    /**
+     * Validates that a value is a object.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static object(value) {
+        if (!value || typeof value !== "object") {
+            throw new TypeError("Expected an object.");
+        }
+    }
+
+    /**
+     * Validates that a value is a object or null.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static "object?"(value) {
+        if (typeof value !== "object") {
+            throw new TypeError("Expected an object or null.");
+        }
+    }
+
+    /**
+     * Validates that a value is a string.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static string(value) {
+        if (typeof value !== "string") {
+            throw new TypeError("Expected a string.");
+        }
+    }
+
+    /**
+     * Validates that a value is a non-empty string.
+     * @param {*} value The value to validate.
+     * @returns {void}
+     * @throws {TypeError} If the value is invalid. 
+     */
+    static "string!"(value) {
+        if (typeof value !== "string" || value.length === 0) {
+            throw new TypeError("Expected a non-empty string.");
+        }
+    }
+
+}
+
+exports.ValidationStrategy = ValidationStrategy;