v0.25.0 — analysis-craft legibility axis

0.25.0 — analysis-craft legibility axis (the ponytail layer)

analysis-craft previously governed only code minimalism — remove machinery, smallest
diff. It now also governs legibility: the code that remains must be readable by a
referee, a replication-package reviewer, or a coauthor.

• New ## Legibility section. Name intermediates in economic units; one conceptual
  step per line (decompose chains that hide a join / filter / winsorize); the referee
  test — can someone follow what each block computes and why in one pass, without
  running it?
• The # why: convention. Every analytical decision (sample restriction, winsorize
  threshold, deflator/base year, fixed effect, cluster level) gets
  # why: <decision> — <reason> at the code site — the code-level echo of
  data-preparation's decisions log.
• Reconciliation note so the two axes don't read as contradictory: minimalism cuts
  machinery; legibility keeps annotated logic; a one-liner-vs-named-steps choice is
  purely legibility, so legibility wins.
• New red-flag and rationalization rows (the slick pipe that hides three decisions; "I
  made it a tight one-liner") plus three legibility trigger-eval cases; the description
  now also fires on "annotate this" / "make it readable for the replication package".

Adapted from ponytail's "don't write code
you don't need" ladder, inverting its fewest-lines goal to readability.