* test(#3569): pin stats phase-id shape — inline-code mentions produce no phantom row
Failing-first regression for #3569: cmdStats' heading scan accepted any
word as a phase id, so prose mentioning ### Phase N: inside inline code
inflated phases_total and disagreed with roadmap analyze. New adversarial
fixture phase-heading-inside-inline-code.md (blockquote + bare mention),
parity assertion against roadmap analyze, and over-narrowing guards for
decimal / milestone-prefixed / letter-prefixed ids.
* fix(#3569): require a digit-bearing phase id in the stats heading scan
cmdStats' hand-rolled heading pattern captured any word as a phase id,
so a ### Phase N: token inside an inline code span (the issue's
blockquote) produced a phantom Not-Started row that could never
complete, inflating phases_total and deflating percent forever. The id
capture is now the canonical #3036 shape roadmap.cts uses (digit
required; letter-prefixed, decimal, and milestone-prefixed ids keep
counting), so stats and roadmap analyze agree.
* fix(#3569): sanction the stats id-shape literal; correct zero-padded expectation
Review findings: the phase-id drift guard requires the // phase-id-owner:
comment directly above the regex (same form as roadmap.cts); the
milestone-prefixed over-narrowing guard must expect normalizePhaseName's
zero-padded 02-01 form, not the raw 2-01 token.
* chore(#3569): add changeset fragment
* chore(#3569): backfill changeset pr number
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Co-authored-by: sim <sim@local>
325fc25c01