classify-size

Use to classify a feature into XS/S/M/L/XL and write docs/features/{slug}/.size plus the pipeline route docs/features/{slug}/.route (quick|standard|full) so later skills know how much of each artifact to produce and how handoffs resolve skips. Triggers on "classify size", "feature size", "is this XS or M for {slug}", "size {slug}", "change route", "/sdd:classify-size {slug}", "класифікуй розмір {slug}", "який розмір фічі", "XS чи M". Asks four AskUserQuestion (PR count / time / new module-API-migration / breaking changes), maps to a size class via the shared size matrix, derives the default route (XS/S→quick, M→standard, L/XL→full), confirms size + route in ONE question, and writes the one-line .size and .route files — the source of truth; the feature_size: frontmatter mirrors in spec.md and sad.md are re-synced to it on every (re)classification.