Task: Review latest architecture and organize tasks

Identity

Review the latest accepted Next.js frontend plus Go backend architecture on main.
Reconcile the ADR, canonical architecture, current integrated state, commitments, and the detailed task-scoped proposal.
Turn the target design into an ordered, dependency-aware implementation backlog without changing application or deployment code.

Treat ADR-003 as an accepted target and ACK-001 as the current deployable truth until compatibility tests and cutover pass.
Put executable compatibility contracts before Go implementation.
Preserve same-origin HTTP/Cookie behavior, tenant authorization, PostgreSQL concurrency functions, one-shot migrations, single-writer cutover, and rollback capability.
Separate production rollout obligations and project-memory debt from the Go migration critical path.

Confirmed the latest architecture is internally consistent across ADR-003, the system overview, module map, data flow, current state, and the detailed proposal.
Organized the work into seven dependency stages: compatibility baseline; Go platform foundation; identity/administration; assets/OSS; billing/usage; jobs/providers/Webhooks/WorkerLoop; frontend/deployment cutover.
Identified the hard gate: no Go route migration should start until executable HTTP, Cookie, authorization, database, job, billing, storage, Webhook, and deployment contracts exist.
Identified decisions needed before or during the baseline: no-logout Cookie compatibility versus forced re-login, public /api/v1 compatibility obligations, and production traffic/backlog limits.
Kept real RDS/ACK rollout, non-root container hardening, and incomplete canonical project-positioning/domain templates as separate workstreams rather than silently expanding the migration.
No application, database, test, or deployment file was changed.

Read the three latest architecture commits (4485899, 064e155, and 7de3300) and their affected records.
Cross-checked ADR-003 with canonical architecture, current state, commitments, the original architecture assessment, and the detailed migration proposal.
Re-inventoried the current API surface: 45 route files and 64 exported HTTP handlers.
Concurrent Task Gate and Planning Gate passed on main at base 7de3300; no peer task or semantic overlap was present.
Application tests were not run because this was a read-only architecture and planning review.

Start with the compatibility-baseline epic and assign one owner per contract-test file or fixture family.
Obtain a product/release decision for Cookie cutover behavior and confirm the support promise for /api/v1 before freezing golden contracts.
Keep the existing Node migration Job during early strangler slices unless a separate accepted decision changes its implementation language.