html_escape.nx

html_escape.nx -- alias stub. nx_html_escape.nx is the canonical HTML entity encoder/decoder (same he_is_safe / he_put / html_escape / he_hex_digit / html_unescape API). This file used to define duplicates which produced linker-level duplicate-symbol errors when the daemon imported both markdown_block.nx (which imports html_escape.nx) AND nx_markdown_block.nx (which imports nx_html_escape.nx). Consumers using `import "html_escape.nx"` resolve via NishiLang's textual import splicing with path-dedup: this stub splices nx_html_escape.nx once, and any other file that also imports "nx_html_escape.nx" directly gets deduped to the same canonical splice. No duplicate symbols. Same shape as syscalls.nx -> nx_syscalls.nx alias. Deprecation: when every "html_escape.nx" consumer migrates to the nx_-prefixed name, delete this stub.