The ansi target, txt table styles, kdesc reference from ref/, typeface and table-width fixes (from dev fcec5e2e77ac)

Since the previous release: Machine::read_string() (the fs::path/std::string
overload pair split); kdesc -c and -u rendered from the ref/ reflection
klammerset; a fit column's tex width measured in TeX over every entry;
@typeface resolving to the family its css declares (a store directory name
now works in html) and hieroglyphs in @unicode_examples set in their
typeface; the ansi target -- plain text with the type styles a terminal can
show, identical to txt once the escape sequences are stripped -- with the
txt @table carrying :header_style, :style and :hline; @block anchoring,
@table spacing and the Image_quality state variable; and the rewritten
doc/klammertext_for_llm.md.

sks/font/font.k

@@ -49,12 +49,16 @@ unchanged.
 @@b.k text : Use a bold weight of the current font for *text* @@
 @@b.html :: <b>*text*</b> @@
 @@b.tex  :: \textbf{*text*} @@
-@@b.txt  :: *text* @@
+# The txt bodies of @b, @i, @u and @ri emit STYLE MARKERS around the text
+# (phases.txt_style_marker), which the txt target strips and the ansi
+# target turns into escape sequences -- see the ansi target in
+# sks/target/target.k.  "#-" glues the marker to the text.
+@@b.txt  :: @eval phases.txt_style_marker("bold") @ #- *text* #- @eval phases.txt_style_marker("bold", False) @ @@
 
 @@i.k text : Use an italic style of the current font for *text* @@
 @@i.html :: <i>*text*</i> @@
 @@i.tex  :: \emph{*text*} @@ # \begin{emph}{*text*}\end{emph} @@
-@@i.txt  :: *text* @@
+@@i.txt  :: @eval phases.txt_style_marker("italic") @ #- *text* #- @eval phases.txt_style_marker("italic", False) @ @@
 
 @@t.k text : Use the currently defined monospace font for *text* @@
 @@t.html :: <span class="tt">*text*</span> @@
@@ -68,11 +72,12 @@ unchanged.
 
 @@u.k text : Underline *text* in the current font @@
 @@u.tex :: \underline{\botstrut{2pt}*text*} @@
+@@u.txt :: @eval phases.txt_style_marker("underline") @ #- *text* #- @eval phases.txt_style_marker("underline", False) @ @@
 
 @@ri.k text : Use a roman italic font for *text* (to override monospace environment) @@
 @@ri.html  :: <span class="ritalic">*text*</span> @@
 @@ri.tex :: \textrm{\textit{*text*}} @@
-@@ri.txt :: *text* @@
+@@ri.txt :: @eval phases.txt_style_marker("italic") @ #- *text* #- @eval phases.txt_style_marker("italic", False) @ @@
 
 @@ts.k scale.float | text : Resize *text* by *scale* @@
 # @@ts.tex :: {\scalefont{*scale*}\em *text*} @@