Enhance development tooling and configuration

- Update VSCode settings for improved development experience
- Add ESLint and Prettier plugins for Astro and Svelte
- Configure pnpm overrides and built dependencies
- Add linting script for Go backend
- Remove Flox environment configuration files

.eslintrc.js

@@ -0,0 +1,75 @@
+module.exports = {
+  root: true,
+  extends: [
+    'eslint:recommended',
+    'plugin:@typescript-eslint/recommended',
+  ],
+  parser: '@typescript-eslint/parser',
+  plugins: ['@typescript-eslint'],
+  env: {
+    browser: true,
+    node: true,
+    es2022: true,
+  },
+  parserOptions: {
+    sourceType: 'module',
+    ecmaVersion: 'latest',
+  },
+  overrides: [
+    // Astro files
+    {
+      files: ['*.astro'],
+      parser: 'astro-eslint-parser',
+      parserOptions: {
+        parser: '@typescript-eslint/parser',
+        extraFileExtensions: ['.astro'],
+      },
+      extends: [
+        'plugin:astro/recommended',
+      ],
+      rules: {
+        'astro/no-conflict-set-directives': 'error',
+        'astro/no-unused-define-vars-in-style': 'error',
+      },
+    },
+    // Svelte files
+    {
+      files: ['*.svelte'],
+      parser: 'svelte-eslint-parser',
+      parserOptions: {
+        parser: '@typescript-eslint/parser',
+      },
+      extends: [
+        'plugin:svelte/recommended',
+      ],
+    },
+    // JavaScript/TypeScript files
+    {
+      files: ['*.js', '*.ts'],
+      rules: {
+        '@typescript-eslint/explicit-function-return-type': ['error', {
+          allowExpressions: true,
+          allowHigherOrderFunctions: true,
+        }],
+        '@typescript-eslint/no-unused-vars': ['error', {
+          argsIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+        }],
+      },
+    }
+  ],
+  rules: {
+    // Project-wide rules
+    'no-console': ['warn', { allow: ['warn', 'error', 'info'] }],
+    'prefer-const': 'error',
+    'eqeqeq': ['error', 'smart'],
+  },
+  ignorePatterns: [
+    'dist',
+    'build',
+    'node_modules',
+    '.astro',
+    '*.go',
+    'backend/build',
+  ],
+};