fix(mindspace): lower page access password minimum to 6 characters

Align publication validation, portal gate HTML, H5 publish UI, MCP docs,
and page-data skill guidance so passwords like 888888 are accepted while
3-character values such as 888 remain rejected.

Co-authored-by: Cursor <cursoragent@cursor.com>

page-data-workspace-bind.mjs

@@ -22,7 +22,7 @@ export function resolvePageDataBindAccess(accessMode = 'public') {
   return publicationInternals.normalizeAccessMode(accessMode);
 }
 
-/** password 模式：用户未传口令时使用 DEFAULT_PAGE_DATA_ADMIN_PASSWORD；<8 位抛错 */
+/** password 模式：用户未传口令时使用 DEFAULT_PAGE_DATA_ADMIN_PASSWORD；<6 位抛错 */
 export function resolvePageDataBindPassword(accessMode, password = null) {
   const mode = resolvePageDataBindAccess(accessMode);
   if (mode !== 'password') return null;