SDK alignment day: type PrescriptionEnvelope, fix getPrescription wrapper, contract tests

[DrAlexHarrison]

The SDK's prescription typings lag the API contract in three places:

• activities.calculatePrescription is typed Promise<NutritionCalculateResponse>. The tier, teaser and trial fields match, but full-tier exact values now live under .prescription.
• activities.getPrescription returns a {prescription, safety} wrapper, not a bare NutritionCalculateResponse.
• The activity import response now carries prescriptions[] (one tier-aware envelope per item) and the request accepts calculate flags, globally and per activity. Batch endpoints debit rate limits per work item, which the client docs should say.

Definition of done: a typed PrescriptionEnvelope, the corrected getPrescription return type, import-time calculate support, and a contract test against the sandbox environment so the typings cannot drift silently.

Until this lands, the curl examples in the quickstart are the reference for these shapes.

[DrAlexHarrison]

Completed and published in SDK0.6.0.

• Accurate tier-aware activity calculation and stored-prescription wrapper types, raw response preservation, nullable warnings, batch success/error indexing, nested pagination and flat full-replacement settings.
• Import calculation is explicit opt-in, supports global/per-item flags and returns per-item outcomes. Both READMEs explain per-item quota/trial accounting.
• Source-backed32-payload contract corpus, static checks and independent minimum-runtime review. Final merged suites: Node124passed/1live-skip; Python149passed/1live-skip.
• Both opt-in live sandbox tests passed against fuel-app-test using fresh email-free synthetic athletes only,14calls per SDK. Naturally observed full/banded/trial calculation, stored wrapper, imports, batches, settings, pagination and feedback. No entitlement overrides, customer records, Stripe or model inference. Exact-tier/teaser alternatives additionally covered by local source-generated fixtures, not claimed as observed live in this run.
• Source PRs: saturday-node17/20 plus18 for adjacent AI streaming; saturday-python12/15 plus13 for AI streaming. Both public registries publish0.6.0, with matching reviewed artifact hashes, fresh registry installations and public-client mock smokes. Annotated v0.6.0 tags point to Node5c5d9b5 and Python1857e7a.

Evidence is preserved in adev .claude/plans/2026-09-19-safe-maintenance/, including sdk-contract-followup.md, sdk-contract-review.md, sdk-sandbox.md and release-followup.md. No backend API, fueling formula or default trial-consumption policy changed for this SDK correction.