docs: Clarify JS import usage and add complete example files

- Explicitly warn users NOT to copy the gem's JavaScript file
- Clarify that activeadmin_quill_editor.js should be imported from the gem
- Add complete working examples from dummy app:
  - Full app/javascript/active_admin.js with proper imports
  - Complete tailwind.config.js with all safelist classes
  - lib/tasks/active_admin.rake for Tailwind builds
- Remove incorrect symlink from dummy app

This prevents users from mistakenly copying the gem's JS file into their
app instead of properly importing it from vendor/assets/javascripts/

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

spec/dummy/app/assets/javascripts/activeadmin_quill_editor.js

@@ -1 +0,0 @@
-../../../../../vendor/assets/javascripts/activeadmin_quill_editor.js

spec/dummy/build_activeadmin_css.js

@@ -1,191 +0,0 @@
-#!/usr/bin/env node
-const fs = require('fs');
-const path = require('path');
-const { spawnSync } = require('child_process');
-
-const root = __dirname;
-const inputPath = path.join(root, 'app/css/active_admin_source.css');
-const vendorCssPath = path.join(root, 'node_modules/quill/dist/quill.snow.css');
-const vendorBubbleCssPath = path.join(root, 'node_modules/quill/dist/quill.bubble.css');
-const tmpPath = path.join(root, 'app/css/__aa_tmp.css');
-const outPath = path.join(root, 'app/assets/builds/active_admin.css');
-
-function build() {
-  // Read source file
-  let srcContent = '';
-  if (fs.existsSync(inputPath)) {
-    srcContent = fs.readFileSync(inputPath, 'utf8');
-  } else {
-    // Create default source if it doesn't exist
-    srcContent = `@tailwind base;
-@tailwind components;
-@tailwind utilities;`;
-  }
-
-  // Extract tailwind directives and body content
-  const lines = srcContent.split(/\r?\n/);
-  const tailwindLines = lines.filter(line => line.includes('@tailwind'));
-  const bodyLines = lines.filter(line =>
-    !line.includes('@tailwind') &&
-    !line.includes('quill/dist/quill')
-  );
-
-  const tailwindDirectives = tailwindLines.join('\n') || '@tailwind base;\n@tailwind components;\n@tailwind utilities;';
-
-  // Read Quill vendor CSS
-  let vendorCss = '';
-
-  if (fs.existsSync(vendorCssPath)) {
-    vendorCss += `\n/* Begin Quill Snow theme CSS */\n`;
-    vendorCss += fs.readFileSync(vendorCssPath, 'utf8');
-    vendorCss += `\n/* End Quill Snow theme CSS */\n`;
-  } else {
-    console.warn('Warning: Quill Snow CSS not found at', vendorCssPath);
-  }
-
-  if (fs.existsSync(vendorBubbleCssPath)) {
-    vendorCss += `\n/* Begin Quill Bubble theme CSS */\n`;
-    vendorCss += fs.readFileSync(vendorBubbleCssPath, 'utf8');
-    vendorCss += `\n/* End Quill Bubble theme CSS */\n`;
-  } else {
-    console.warn('Warning: Quill Bubble CSS not found at', vendorBubbleCssPath);
-  }
-
-  const body = bodyLines.join('\n');
-
-  // Add custom Quill styles for ActiveAdmin integration
-  const customStyles = `
-/* Custom Quill integration styles */
-.quill-editor {
-  @apply border border-gray-300 rounded-md;
-}
-
-.ql-toolbar {
-  @apply border-b-0 rounded-t-md;
-}
-
-.ql-container {
-  @apply rounded-b-md;
-}
-
-.ql-editor {
-  @apply min-h-[200px];
-}
-
-/* Dark mode support */
-.dark .quill-editor {
-  @apply border-gray-600;
-}
-
-.dark .ql-toolbar {
-  @apply bg-gray-800 border-gray-600;
-}
-
-.dark .ql-container {
-  @apply bg-gray-900 border-gray-600;
-}
-
-.dark .ql-editor {
-  @apply text-gray-100;
-}
-
-/* Fix toolbar button styles */
-.ql-toolbar button:hover {
-  @apply bg-gray-100 dark:bg-gray-700;
-}
-
-/* Ensure icons are visible in dark mode */
-.dark .ql-toolbar button svg {
-  @apply text-gray-300;
-}
-
-.dark .ql-toolbar button:hover svg {
-  @apply text-white;
-}
-
-.dark .ql-toolbar .ql-stroke {
-  stroke: #9ca3af !important;
-}
-
-.dark .ql-toolbar .ql-fill {
-  fill: #9ca3af !important;
-}
-
-.dark .ql-toolbar button:hover .ql-stroke {
-  stroke: white !important;
-}
-
-.dark .ql-toolbar button:hover .ql-fill {
-  fill: white !important;
-}`;
-
-  // Combine all CSS - Tailwind directives, vendor CSS, custom styles, then body
-  const tmpCss = `${tailwindDirectives}\n${vendorCss}\n${customStyles}\n${body}`;
-
-  // Create directories if they don't exist
-  const cssDir = path.dirname(tmpPath);
-  if (!fs.existsSync(cssDir)) {
-    fs.mkdirSync(cssDir, { recursive: true });
-  }
-
-  const buildDir = path.dirname(outPath);
-  if (!fs.existsSync(buildDir)) {
-    fs.mkdirSync(buildDir, { recursive: true });
-  }
-
-  fs.writeFileSync(tmpPath, tmpCss, 'utf8');
-
-  // Run tailwindcss build
-  const res = spawnSync('npx', [
-    'tailwindcss',
-    '-c', path.join(root, 'tailwind-active_admin.config.js'),
-    '-i', tmpPath,
-    '-o', outPath,
-    '--minify'
-  ], { stdio: 'inherit', cwd: root });
-
-  if (res.status !== 0) {
-    console.error('Tailwind build failed');
-    process.exit(res.status || 1);
-  }
-
-  // Clean up temp file
-  fs.unlinkSync(tmpPath);
-
-  console.log(`ActiveAdmin CSS built successfully: ${outPath}`);
-  const stats = fs.statSync(outPath);
-  console.log(`File size: ${(stats.size / 1024).toFixed(2)} KB`);
-}
-
-// Support watch mode
-if (process.argv.includes('--watch')) {
-  console.log('Watching for changes...');
-
-  // Initial build
-  build();
-
-  // Watch for changes
-  const watchPaths = [
-    inputPath,
-    path.join(root, 'tailwind-active_admin.config.js'),
-    path.join(root, 'app/admin'),
-    path.join(root, 'app/views')
-  ];
-
-  const chokidar = require('chokidar');
-  const watcher = chokidar.watch(watchPaths, {
-    ignored: /node_modules|\.git|__aa_tmp\.css/,
-    persistent: true
-  });
-
-  watcher.on('change', () => {
-    console.log('Changes detected, rebuilding...');
-    try {
-      build();
-    } catch (err) {
-      console.error('Build error:', err);
-    }
-  });
-} else {
-  build();
-}