Should you build your own Smartsheet?

Build a personal replacement for Smartsheet in an empty repository.
Use Next.js 15, TypeScript, Tailwind CSS, PostgreSQL, Drizzle ORM, and Docker Compose; do not offer alternative stacks.
The core loop is: manage structured project rows with formulas, forms, automations, and reports, and track work through milestones, comments, and a searchable activity history for a small team.
Make the first run work locally with one documented command.
Store all user data locally by default and make export straightforward.
Put secrets in .env, ship .env.example, and never commit credentials.
Implement organizations, projects, members, issues, labels, cycles, and milestones.
Provide list, kanban, and simple timeline views backed by one canonical issue model.
Add comments, mentions, assignments, watchers, and a complete activity log.
Implement project roles for owner, member, and viewer and test every mutation.
Add search, CSV import or export, email notifications, and daily database backups.
Ship Docker Compose, health checks, migrations, seed data, and an admin recovery command.
Include clear empty, loading, success, and recoverable error states.
Add input validation, safe filenames, and graceful handling of unavailable APIs.
Write focused tests for the core transformation and one end-to-end happy path.
Create a README with setup, architecture, permissions, data location, and backup steps.
Do not add accounts, billing, telemetry, analytics, or a hosted control plane.
Deliberately leave out hundreds of external integrations.
Deliberately leave out enterprise portfolio planning and SSO.
Deliberately leave out native mobile clients and vendor-operated uptime.
Finish by running the tests and listing the exact commands used.