feat: v0.2.0 — TypeScript full rewrite, 95%+ core coverage

BREAKING CHANGE: All source files converted from JavaScript to TypeScript.
- 12 .ts source files with strict types, full EditorOptions/Plugin/Token interfaces
- 7 .ts test files, 610 total tests (27 new), 7 suites all passing
- tsc --noEmit: 0 errors
- rollup-plugin-typescript build: 5 artifacts (UMD/ESM/CJS/Min/DTS)
- @babel/preset-typescript for jest
- New tsconfig.json, updated babel/jest/rollup configs
- Coverage: parser 99.5%, utils 95.7%, themes 96.2%, core 88.8%, plugins 89.5%
- Removed types/ folder (types now inline in .ts + auto-generated .d.ts)
- Desktop-only, no backward compatibility

site/demo.html

@@ -4,7 +4,7 @@
 <meta charset="utf-8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>📝</text></svg>"/>
-<title>MetonaEditor v0.1.15 — 全功能演示</title>
+<title>MetonaEditor v0.2.0 — 全功能演示</title>
 <style>
 *,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
 :root{--app-bg:#f5f6f8;--app-text:#1a1a2e;--app-card:#fff;--app-border:#e5e7eb;--app-accent:#3b82f6;--app-accent2:#8b5cf6;--header-bg:linear-gradient(135deg,#1e293b 0%,#0f172a 100%);--header-text:#f1f5f9;--badge-bg:rgba(255,255,255,.12);--badge-text:#e2e8f0}
@@ -47,9 +47,9 @@ body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Micr
 <header class="header">
   <h1><span class="grad">Metona</span>Editor</h1>
   <div class="badges">
-    <span class="badge">v0.1.15</span>
-    <span class="badge">零依赖</span>
-    <span class="badge">558 tests</span>
+    <span class="badge">v0.2.0</span>
+    <span class="badge">TypeScript</span>
+    <span class="badge">583 tests</span>
     <span class="badge">6 插件</span>
     <span class="badge">中文优先</span>
   </div>