Width and height argtypes, kdesc --argtypes from ref/, txt @define/@left_right/@columns, kdiag --check value validation (from dev d6993110e9b3)

Also: the klammertext argtype (descriptions kept as source), txt table
wrapping and :hpos/:offset, @c between ‹ ›, txt section headings, the
ktext newline-only trim, capitalize(), and the argtype test suite.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

sks/target/html_util.py

@@ -223,11 +223,11 @@ def hpos_container(element, hpos, offset=None):
     # coded, and only in html.)
     styles = []
     if hpos not in ("left", "center", "right", "none"):
-        length, _, _ = kutil.parse_length("html", hpos, 1)
+        length, _, _ = kutil.parse_width("html", hpos)
         styles.append(f"margin-left: {length}")
         hpos = "indent"
     if offset and offset not in ("0", "0pt") and hpos in ("left", "right", "indent"):
-        length, _, _ = kutil.parse_length("html", offset, 1)
+        length, _, _ = kutil.parse_width("html", offset)
         side = "right" if hpos == "right" else "left"
         styles.append(f"padding-{side}: {length}")
     result = E("div").cls("hpos_" + hpos).body(element)