refine(pseudo): markers are pointing handles, not footnotes

Forbid the footnote/legend pattern: explanations for a marked
line must live inline at that line (rule 2), never in a
post-block `[1] = …, [2] = …` key that forces the reader to
bounce between code and a legend below it. A marker is purely a
label so the user can point ('expand [2]'); a line that reads
for itself carries a bare marker and no comment.

Rework rule 4 accordingly, add the Iron Law line, guard rule 1's
supporting-prose clause against becoming a legend, and rewrite
the worked example's trailing commentary to demonstrate inline
explanation with no marker key. Frontmatter and README updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -36,8 +36,10 @@ One **conversational skill** stands outside the pipeline entirely:
 `pseudo` (typed `/pseudo`) switches replies into commented,
 human-readable pseudocode for explaining code — each answer opens
 with a source-file-and-line anchor, marks notable steps with
-reference markers the user can point back at, sketches the
-layout of the data structures the code touches alongside the
+reference markers that are pointing handles for the user (not
+footnotes — explanations stay inline at the code, never in a
+legend below), sketches the layout of the data structures the
+code touches alongside the
 flow, reduces the irrelevant to stubs, and omits low-level
 mechanics. The pseudocode leans on the source language's idiom
 in a language-tagged fence so it renders with syntax