Docs: add zh-CN entrypoint translations (#6300)

* Docs: add zh-CN entrypoint translations

* Docs: harden docs-i18n parsing

scripts/docs-i18n/masking.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var (
+	inlineCodeRe  = regexp.MustCompile("`[^`]+`")
+	angleLinkRe   = regexp.MustCompile(`<https?://[^>]+>`)
+	linkURLRe     = regexp.MustCompile(`\[[^\]]*\]\(([^)]+)\)`)
+	placeholderRe = regexp.MustCompile(`__OC_I18N_\d+__`)
+)
+
+func maskMarkdown(text string, nextPlaceholder func() string, placeholders *[]string, mapping map[string]string) string {
+	masked := maskMatches(text, inlineCodeRe, nextPlaceholder, placeholders, mapping)
+	masked = maskMatches(masked, angleLinkRe, nextPlaceholder, placeholders, mapping)
+	masked = maskLinkURLs(masked, nextPlaceholder, placeholders, mapping)
+	return masked
+}
+
+func maskMatches(text string, re *regexp.Regexp, nextPlaceholder func() string, placeholders *[]string, mapping map[string]string) string {
+	matches := re.FindAllStringIndex(text, -1)
+	if len(matches) == 0 {
+		return text
+	}
+	var out strings.Builder
+	pos := 0
+	for _, span := range matches {
+		start, end := span[0], span[1]
+		if start < pos {
+			continue
+		}
+		out.WriteString(text[pos:start])
+		placeholder := nextPlaceholder()
+		mapping[placeholder] = text[start:end]
+		*placeholders = append(*placeholders, placeholder)
+		out.WriteString(placeholder)
+		pos = end
+	}
+	out.WriteString(text[pos:])
+	return out.String()
+}
+
+func maskLinkURLs(text string, nextPlaceholder func() string, placeholders *[]string, mapping map[string]string) string {
+	matches := linkURLRe.FindAllStringSubmatchIndex(text, -1)
+	if len(matches) == 0 {
+		return text
+	}
+	var out strings.Builder
+	pos := 0
+	for _, span := range matches {
+		fullStart := span[0]
+		urlStart, urlEnd := span[2], span[3]
+		if urlStart < 0 || urlEnd < 0 {
+			continue
+		}
+		if fullStart < pos {
+			continue
+		}
+		out.WriteString(text[pos:urlStart])
+		placeholder := nextPlaceholder()
+		mapping[placeholder] = text[urlStart:urlEnd]
+		*placeholders = append(*placeholders, placeholder)
+		out.WriteString(placeholder)
+		pos = urlEnd
+	}
+	out.WriteString(text[pos:])
+	return out.String()
+}
+
+func unmaskMarkdown(text string, placeholders []string, mapping map[string]string) string {
+	out := text
+	for _, placeholder := range placeholders {
+		original := mapping[placeholder]
+		out = strings.ReplaceAll(out, placeholder, original)
+	}
+	return out
+}
+
+func validatePlaceholders(text string, placeholders []string) error {
+	for _, placeholder := range placeholders {
+		if !strings.Contains(text, placeholder) {
+			return fmt.Errorf("placeholder missing: %s", placeholder)
+		}
+	}
+	return nil
+}