release: v0.1.4 — parser enhancement, new syntax, performance optimization

feat(parser): comprehensive Markdown parser enhancement
- Add nested list support (multi-level unordered/ordered, mixed nesting)
- Add Setext headings (=== / ---)
- Add indented code blocks (4-space indent)
- Add HTML comment passthrough (<!-- -->)
- Add entity reference protection (&amp; &#169;)
- Add ordered list start attribute
- Add link title single-quote support
- Add LaTeX math formulas ($inline$ / $$block$$)
- Add footnote support ([^1] ref + [^1]: definition)
- Add definition lists (term\n: definition)
- Extend emoji map from 85 to 150+ common emojis
- Fix backtick code block matching (CommonMark spec)
- Fix italic regex character truncation (lookbehind assertions)
- Fix superscript/subscript/strikethrough ambiguity
- Fix blockquote prefix handling (>text without space)
- Enhance safeUrl filtering (additional protocol checks)
- Enhance slugify (Unicode NFKC normalization)

perf(parser): single-pass inline scanning, render cache, pre-compiled regex
- Replace 14-step chained regex with unified single-pass scanInline()
- Add cachedRenderInline() with FIFO LRU eviction (300-entry cap)
- Pre-compile 15+ static regex constants for block boundary detection
- Skip redundant style='text-align:left' on default-aligned table cells

style(parser): add CSS for footnotes, definition lists, math formulas, sup/sub

test(parser): 44 new test cases covering all v0.1.4 syntax additions (469 total)

chore: bump version 0.1.3 → 0.1.4 across all source files, docs, site pages

site/docs.html

@@ -175,7 +175,7 @@
 
 <header class="docs-header">
   <h1><span class="grad">文档</span></h1>
-  <p class="sub">MetonaEditor v0.1.3 完整 API、配置与使用指南</p>
+  <p class="sub">MetonaEditor v0.1.4 完整 API、配置与使用指南</p>
 </header>
 
 <div class="container">
@@ -598,7 +598,7 @@ i18nUtils<span class="c-punc">.</span><span class="c-fn">formatDate</span><span
 
 <footer>
   <div class="container">
-    MetonaEditor v0.1.3 · <a href="https://git.metona.cn/MetonaTeam/MetonaEditor" target="_blank" rel="noopener">源码仓库</a> · MIT License
+    MetonaEditor v0.1.4 · <a href="https://git.metona.cn/MetonaTeam/MetonaEditor" target="_blank" rel="noopener">源码仓库</a> · MIT License
   </div>
 </footer>