feat: hs meta archetypes/decks — live win-rate/tier/deck-code (Firestone)

[say8425]

Summary

Adds live Hearthstone meta to the CLI via two new hs meta subcommands, backed by Firestone (firestoneapp.com), used with written permission:

• hs meta archetypes — archetype tier view (aggregated win rate per archetype)
• hs meta decks — individual decks with deck codes

Flags (both): --game-format standard|wild|twist, --rank legend|top-2000-legend|competitive|legend-diamond|diamond|platinum|bronze-gold|all, --period last-patch|past-3|past-7|past-20|current-season, --min-games N, --sort wilson|winrate|games, --limit N, plus existing -f table|json.

Methodology (why this isn't naive)

Ranking by raw win rate surfaces small-sample flukes, so rows are ranked by the Wilson score lower bound (the Reddit/Yelp standard), shown alongside raw WR and a ±margin-of-error column. Sample-size floor (decks 400 / archetypes 2000, overridable). Heuristic tier bands (S/A/B/C/D) computed on the Wilson lower bound so a 40/50 spike can't inflate to tier S. Rank brackets are never silently blended (low ranks skew). Defaults: legend / last-patch.

Architecture (small, focused units)

• src/services/stats-math.ts — pure wilsonLower / marginOfError / tierBand
• src/services/archetype-names.ts — Firestone translations slug→display name (24h cache)
• src/services/meta-stats.ts — buildMetaUrl + fetchMeta (CDN JSON, 1h cache, UA header, stale-cache fallback) + pure rankArchetypes/rankDecks
• src/services/formatter.ts — formatMetaStats (table/json, attribution header, low-sample flag)
• src/commands/meta.ts — static metadata types unchanged; new live types validated + wired

Deck codes from hs meta decks pipe into hs deck <code>. Attribution in output + all 6 READMEs. Does not touch Firestone's rate-sensitive per-deck Lambda endpoint.

Test Plan

• bun run check — lint 0, fmt:check clean, typecheck 0, 75 tests pass
• Pure logic covered by committed fixtures: wilson/MoE/tier, buildUrl, rank filter/sort/limit/deckcode, slug→display, formatMetaStats json+table+low-sample
• e2e live: meta archetypes (real data, wilson sort, ±MoE), meta decks -f json deckcode → hs deck decodes a real deck, 1h cache hit, invalid-flag guard exits 1
• static meta classes/sets unchanged (no regression)
• CI green on this PR

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