chore: Add ESLint 9, TypeScript ESLint, and Prettier configuration

.prettierignore

@@ -0,0 +1,21 @@
+# Dependencies
+node_modules/
+
+# Build outputs
+.next/
+out/
+dist-tests/
+
+# Public assets
+public/
+
+# WASM files
+wasm/
+
+# Package manager files
+package-lock.json
+pnpm-lock.yaml
+
+# Generated files
+*.min.js
+*.min.css

.prettierrc

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+{
+  "semi": true,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "es5",
+  "printWidth": 100,
+  "bracketSpacing": true,
+  "arrowParens": "always",
+  "endOfLine": "lf"
+}

eslint.config.mjs

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+import nextConfig from 'eslint-config-next';
+import eslintConfigPrettier from 'eslint-config-prettier';
+import tseslint from 'typescript-eslint';
+
+const eslintConfig = [
+  // Global ignores (must be first)
+  {
+    ignores: [
+      'dist-tests/',
+      'node_modules/',
+      'public/',
+      'wasm/',
+      '.next/',
+      'out/',
+    ],
+  },
+
+  // Next.js recommended config (includes TypeScript ESLint, React, etc.)
+  ...nextConfig,
+
+  // TypeScript-specific rule overrides
+  {
+    files: ['**/*.ts', '**/*.tsx'],
+    plugins: {
+      '@typescript-eslint': tseslint.plugin,
+    },
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'warn',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
+      ],
+    },
+  },
+
+  // General rules for all files
+  {
+    rules: {
+      'no-console': ['warn', { allow: ['warn', 'error'] }],
+      'prefer-const': 'error',
+      eqeqeq: ['error', 'always'],
+    },
+  },
+
+  // Prettier config (must be last to override formatting rules)
+  eslintConfigPrettier,
+];
+
+export default eslintConfig;