feat(native-el-ui): convert all component files to el-html vessel API

Replaced raw HTML heredoc returns with native el_ function calls across
all 21 component files. styles.el intentionally excluded.

src/viral.el

@@ -2,5 +2,5 @@
 // Removed — section taken out per design decision.
 
 fn viral() -> String {
-    return ""
+    ""
 }