sdk: round-4 CLI follow-ups — PM intent tokenAmount guard + resolveExpiration/collection-options specs (#0431-#0433)

[trevormil]

Summary

Stacked on #243 (base feat/0428-cli-followups-r3). Round-4 of the rolling audit — the codebase is converging; this is a tight batch (1 producer-correctness bug + 2 real coverage gaps, one a self-caught round-2 miss).

• #0431 Canonical buildPredictionMarketBuyIntent / buildPredictionMarketSellIntent now throw on non-positive tokenAmount. Previously the slim bb build pm-*-intent builders guarded amount>0 but the end-user bb prediction-markets buy/sell called the canonical fn directly with BigInt(opts.tokenAmount) — --token-amount 0/-5 flowed through. Guard now lives at the producer root (the #0422 pattern), so both surfaces enforce it. Also: isUserRecurringApproval's charge-period cap is now bigint-exact (was BigInt(Math.min(Number(intervalLength), …)) — lossy; now matches the producer userRecurringApproval's pure-bigint cap — same producer↔recognizer-drift class as #0425).
• #0432 Direct resolveExpiration unit spec. The duration branch (now + parseDuration) was only exercised indirectly via a determinism row that normalizes the time window out; now all three branches + the ≥10-digit ms-since-epoch heuristic boundary + invalid input are directly asserted.
• #0433 collection-options.spec.ts — normalizeCollection (envelope unwrap / never-throws / raw-fallback) + validateCollectionOrExit (not-found→exit2 / errors+warnings→exit2 / BB_QUIET gate / silent-when-valid). The #0429 ticket scoped this spec but it wasn't written (round-2 miss; caught by the round-3 audit).

Scope notes

• 0431: the slim builders' redundant pre-check left in place (no churn). bb nfts bid/list --token-amount/--max-fills/--max-sales left permissive — symmetric across build & end-user (≤0 → chain-accepted no-op), not an asymmetry; broad count-flag validation would be speculative.
• 0433: bigint-value assertions intentionally omitted — BitBadgesCollection.convert(BigIntify) is that class's own separately-tested concern and needs a full fixture; the boundary contract (unwrap/never-throw/fallback) is what #0429 actually fixed and is schema-independent.
• The round-3 CLI-DRY audit reported converged (the only residue — 2 callApi copies vs shared callIndexer — is below the ≥3 dedup bar; not filed, per no-churn).

Validation

• Build clean — tsc ×2, no circular dependencies.
• Unit: 143 suites / 3108 tests green (+1 suite, +16 tests).
• Integration: 20 suites / 186 tests green.

Test plan

• bb prediction-markets buy-yes … --token-amount 0 now errors (parity with bb build pm-buy-intent)
• bun run build / test:unit / test:integration green

🤖 Generated with Claude Code

Stack: main ← #242 ← #243 ← this.