Run the complete product for the first time

You are helping me run TabTin for the first time so I can build my own product on it. Complete the startup and verification yourself; do not stop at a list of commands for me to run.

Before you begin

Read AGENTS.md, docs/agent/setup.md, and docs/agent/commands.md, then inspect dev.sh and apps/tabtin-electron. Check the worktree, occupied ports, Docker, and the root environment configuration. Do not create another .env, stop unrelated processes, or remove any of my data or code changes.

Work to complete

1. Confirm all local prerequisites and safely install anything essential that is missing, recording what changed.
2. Follow the repository’s current development flow to start the database, cache, Django, background jobs, collaboration service, and realtime service.
3. After backend health checks pass, start Electron in a persistent development terminal rather than a short-lived background process.
4. For a port conflict, identify the owning process first and only replace a process that clearly belongs to an old TabTin development stack.
5. When startup fails, read the relevant logs, find the cause, and continue through the fix. Do not leave a restart step for me.

Verification

Use the repository’s health endpoints for the API, collaboration, and realtime services. Confirm that the Electron development server is reachable and that the page or console has no startup-blocking error. Record the actual ports and service states. If an optional component stays offline, explain whether it affects the next product-customization task.

Final report

List the services started, addresses, health results, problems fixed, configuration changed, and the safe way to stop the development environment. Recommend whether deployment or rebranding is the more appropriate next step. Do not commit or push unless I explicitly ask.