feat(pseudo): show data-structure layout, not just control flow

Add rule 7: alongside the control flow, sketch the layout of the
data structures the code in focus reads or builds — record
fields, collection nesting, variant cases relevant to the
question — placed beside the code that touches them and reduced
in the same spirit (only the fields on the topic path). When the
data layout is the question, it leads and the flow becomes the
stub. Iron Law, worked example, frontmatter, and README updated
to match.

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

README.md

@@ -36,9 +36,11 @@ 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, reduces the
-irrelevant to stubs, omits low-level mechanics, and never runs
-longer than one screen. It dispatches no agents.
+reference markers the user can point back at, sketches the
+layout of the data structures the code touches alongside the
+flow, reduces the irrelevant to stubs, omits low-level
+mechanics, and never runs longer than one screen. It dispatches
+no agents.
 
 Vocabulary is configurable. A **cycle** is one round in the
 pipeline graph; your project may call it a *release*, an *epic*,