parse_html_children consumed the closing `}` of the outer El function as
HTML text content when a tag was left open across a function boundary
(e.g. `page_open()` opens `<body>` without a closing `</body>`). Fix:
stop the children loop when the current token is RBrace — that token
belongs to the El function, not the HTML tree.
Add html_raw() and html_escape() builtins to el_runtime so templates
can interpolate trusted raw HTML and safely escape user-supplied content.
Rename elc-new.c → elc.c as the canonical compiler source; rebuild
elc binary from it.
