release: v0.1.2 — readOnly, new syntax, plugins, optimizations

Features:
- feat(core): readOnly mode with config option and setReadOnly() API
- feat(parser): superscript ^text^ and subscript ~text~ support
- feat(parser): highlight/mark ==text== syntax
- feat(parser): table column alignment with colons (:---, :---:, ---:)
- feat(parser): emoji shortcodes 😄 → 😊 (80+ common emojis)
- feat(plugins): imagePaste preset — paste clipboard images as base64
- feat(core): instance-level beforeRender/afterRender events
- feat(styles): print stylesheet (@media print)
- feat(styles): mark element CSS styling
- feat(styles): readOnly mode CSS (.me-readonly)

Optimizations:
- perf(core): history debounce now configurable via historyDebounce option
- perf(core): skip _render() in edit-only mode (already guarded)
- fix(core): divider drag division-by-zero guard
- fix(core): config.style deep merge with DEFAULTS
- fix(core): scroll position preserved across mode switches

Tests:
- 9 new test cases: readOnly (3), parser syntax (6)
- Total: 418 tests passing (+9 from v0.1.1)

Chores:
- version bump 0.1.1 → 0.1.2
- TypeScript definitions updated for new APIs

src/plugins.js

@@ -1,7 +1,7 @@
 /**
  * MetonaEditor Plugins - 插件系统
  * @module plugins
- * @version 0.1.1
+ * @version 0.1.2
  * @description 插件管理器 + 预设插件（autoSave / exportTool / searchReplace）
  *
  * 插件约定：
@@ -419,6 +419,47 @@ const searchReplacePlugin = {
   },
 };
 
+/**
+ * 图片粘贴插件
+ * 监听 textarea 粘贴事件，自动将剪贴板中的图片转换为 base64 data URI 并插入。
+ */
+const imagePastePlugin = {
+  name: 'imagePaste',
+  description: '粘贴图片自动转为 base64 内联',
+
+  _onPaste: null,
+
+  install(editor) {
+    if (!editor || !editor.textarea || typeof document === 'undefined') return;
+
+    this._onPaste = (e) => {
+      const items = e.clipboardData && e.clipboardData.items;
+      if (!items) return;
+      for (const item of items) {
+        if (item.type && item.type.startsWith('image/')) {
+          e.preventDefault();
+          const reader = new FileReader();
+          reader.onload = () => {
+            const dataUri = reader.result;
+            const name = `image-${Date.now().toString(36)}.png`;
+            editor.insert(`![${name}](${dataUri})\n`);
+          };
+          reader.readAsDataURL(item.getAsFile());
+          break;
+        }
+      }
+    };
+    editor.textarea.addEventListener('paste', this._onPaste);
+  },
+
+  destroy(editor) {
+    if (this._onPaste && editor && editor.textarea) {
+      editor.textarea.removeEventListener('paste', this._onPaste);
+    }
+    this._onPaste = null;
+  },
+};
+
 /**
  * 预设插件注册表
  */
@@ -426,6 +467,7 @@ const presetPlugins = {
   autoSave: autoSavePlugin,
   exportTool: exportToolPlugin,
   searchReplace: searchReplacePlugin,
+  imagePaste: imagePastePlugin,
 };
 
 /**