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/demo.html

@@ -313,9 +313,34 @@
       '',
       '| 名称 | 值 |',
       '| --- | --- |',
-      '| 版本 | 0.1.3 |',
+      '| 版本 | 0.1.4 |',
       '| 依赖 | 零 |',
-      '| 测试 | 390+ |',
+      '| 测试 | 469+ |',
+      '',
+      '## 新增语法',
+      '',
+      '### 数学公式',
+      '',
+      '- 行内：$E=mc^2$',
+      '- 块级：$$\\int_0^\\infty e^{-x}dx$$',
+      '',
+      '### 嵌套列表',
+      '',
+      '- 一级',
+      '  - 二级',
+      '    - 三级',
+      '',
+      '### 脚注',
+      '',
+      '这是带脚注的文字[^1]',
+      '',
+      '[^1]: 这是脚注内容',
+      '',
+      '### 定义列表',
+      '',
+      'Markdown',
+      ': 一种轻量级标记语言。',
+      ': 由 John Gruber 创建。',
       '',
       '## 任务列表',
       '',