deps(npm): bump eslint from 8.57.1 to 10.1.0 in /frontend/taskdeck-web (#487)

* deps(npm): bump eslint from 8.57.1 to 10.1.0 in /frontend/taskdeck-web

Bumps [eslint](https://github.com/eslint/eslint) from 8.57.1 to 10.1.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Commits](eslint/eslint@v8.57.1...v10.1.0)

---
updated-dependencies:
- dependency-name: eslint
  dependency-version: 10.1.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Migrate ESLint 8→10: flat config, upgrade eslint-plugin-vue to v10

- Upgrade eslint-plugin-vue from ^9.33.0 to ^10.8.0 (required for ESLint 10 compat)
- Add @eslint/js and globals as devDependencies
- Replace .eslintrc.cjs with eslint.config.js (flat config format)
- Update lint script to drop legacy --ext flag
- Remove stale eslint-disable-next-line in demo-seed.mjs (no-constant-condition no longer flagged)

Resolves ERESOLVE peer conflict: eslint-plugin-vue@9 requires eslint<10

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Chris0Jeky <jeky.tck@gmail.com>

Author: dependabot[bot]

frontend/taskdeck-web/.eslintrc.cjs

@@ -0,0 +1,98 @@
+import pluginVue from 'eslint-plugin-vue'
+import tsParser from '@typescript-eslint/parser'
+import tsPlugin from '@typescript-eslint/eslint-plugin'
+import eslint from '@eslint/js'
+import vueParser from 'vue-eslint-parser'
+import globals from 'globals'
+
+export default [
+  // Base recommended config
+  eslint.configs.recommended,
+
+  // TypeScript and Vue source files
+  {
+    files: ['**/*.ts', '**/*.vue'],
+    plugins: { '@typescript-eslint': tsPlugin },
+    languageOptions: {
+      parser: vueParser,
+      parserOptions: {
+        parser: tsParser,
+        sourceType: 'module',
+        ecmaVersion: 'latest',
+        extraFileExtensions: ['.vue'],
+      },
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+        ...globals.es2022,
+      },
+    },
+    rules: {
+      ...tsPlugin.configs.recommended.rules,
+      // TypeScript handles undefined checking, no-undef causes false positives with TS namespaces
+      'no-undef': 'off',
+      'no-console': 'off',
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
+      ],
+    },
+  },
+
+  // JavaScript / MJS scripts
+  {
+    files: ['**/*.mjs', '**/*.js'],
+    languageOptions: {
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+        ...globals.es2022,
+      },
+    },
+    rules: {
+      'no-control-regex': 'off',
+    },
+  },
+
+  // Vue-specific rules
+  ...pluginVue.configs['flat/essential'],
+  {
+    files: ['**/*.vue'],
+    rules: {
+      'vue/multi-word-component-names': 'off',
+      'vue/attributes-order': 'off',
+      'vue/html-quotes': 'off',
+      'vue/html-self-closing': 'off',
+      'vue/max-attributes-per-line': 'off',
+      'vue/singleline-html-element-content-newline': 'off',
+    },
+  },
+
+  // Test files (vitest)
+  {
+    files: ['**/*.spec.ts', '**/*.test.ts', 'src/tests/**/*.ts', 'tests/**/*.ts'],
+    languageOptions: {
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+        ...globals.es2022,
+        ...globals.vitest,
+      },
+    },
+    rules: {
+      '@typescript-eslint/no-unused-expressions': 'off',
+    },
+  },
+
+  // Ignores
+  {
+    ignores: [
+      'dist/**',
+      'coverage/**',
+      'test-results/**',
+      'playwright-report/**',
+      'node_modules/**',
+    ],
+  },
+]