Plan `plan-1.9.2-deploy-smoke-test-production-host` — `/massu-deploy` smoke tests now target the canonical production host (`https://massu.ai`) instead of the per-deploy Vercel preview URL.

Plan plan-1.9.2-deploy-smoke-test-production-host — /massu-deploy smoke tests now target the canonical production host (https://massu.ai) instead of the per-deploy Vercel preview URL. Closes the structural bug discovered 2026-05-15 during the 1.9.1 ceremony where every smoke test on /, /docs, /changelog, /overview returned HTTP 401 against the auth-gated preview URL — making the gate enshrined in CR-48 Stage D unable to actually verify production. Adds alias-propagation poll (Vercel CLI vercel ls --prod matches the new deploy's hostname prefix) so smoke tests only run after the production alias has been updated to point to the new deploy; FAIL-with-bypass on timeout (MASSU_SKIP_ALIAS_PROPAGATION_CHECK=1) mirroring CR-48 staleness gate pattern. Structural drift-prevention: vitest massu-deploy-script-shape.test.ts (4 DEPLOY-SHAPE assertions including a slash-command doc drift-guard) parses scripts/massu-deploy.sh and asserts smoke tests target PRODUCTION_HOST, not DEPLOY_URL. The bug class — "deploy script silently 401s its own smoke tests" — becomes structurally impossible to reintroduce without test failure.

Fixed

• scripts/massu-deploy.sh Step 5 smoke-test target — was ${DEPLOY_URL}${ROUTE} (auth-gated preview URL, always 401); now ${PRODUCTION_HOST}${ROUTE} (canonical production domain, returns real HTTP status). Uses curl -sL to follow redirects so /docs (307 → /docs/getting-started → 200) passes correctly.
• Final-report honesty: was hardcoded Custom domain: https://massu.ai; now Production target: $PRODUCTION_HOST (reflects env-overrides for staging dry-runs).

Added

• scripts/massu-deploy.sh Step 4.5 Alias Propagation poll — uses vercel ls --prod (already-authenticated CLI) to detect when the new deploy is the production-alias target. FAIL-with-bypass on timeout (MASSU_SKIP_ALIAS_PROPAGATION_CHECK=1 env-bypass logged to stderr). The header-polling approach (x-vercel-deployment-url) was empirically ruled out: live curl -sI https://massu.ai/ returns x-vercel-id but not x-vercel-deployment-url.
• PRODUCTION_HOST + ALIAS_PROPAGATION_TIMEOUT_SECS constants in scripts/massu-deploy.sh with env-var overrides (MASSU_PRODUCTION_HOST, MASSU_ALIAS_PROPAGATION_TIMEOUT_SECS). Input validation: URL regex + integer ≤600 cap.
• website/src/tests/massu-deploy-script-shape.test.ts — 4 drift-guard assertions (DEPLOY-SHAPE-01..04) parsing the bash script + slash-command doc via readFileSync. Asserts smoke loop uses ${PRODUCTION_HOST} not ${DEPLOY_URL}, propagation block precedes smoke block, and doc cites the same default + env-var names. Empty-body and curl-line-count guards prevent silent-pass on delimiter rename.
• .claude/commands/massu-deploy.md — env-var override table; Step 4.5 added to pre-flight checks list.

Verification

• bash -n scripts/massu-deploy.sh — exit 0.
• cd website && npx vitest run src/tests/massu-deploy-script-shape.test.ts — 4/4 pass.
• cd packages/core && npx tsc --noEmit — 0 errors.
• cd website && npx tsc --noEmit — 0 errors.
• bash scripts/massu-pattern-scanner.sh — all 16 checks PASS.
• bash scripts/massu-plan-status-validator.sh — PASS.
• bash scripts/massu-plan-commit-drift.sh — PASS.
• Live pre-deploy baseline (2026-05-15): https://massu.ai/ → 200; /docs → 307 → 200 (handled via -L); /changelog → 200; /overview → 200.