[PM-36230] Update project default config for better out-of-the-box usage

[jprusik]

🎟️ Tracking

PM-36230

📔 Objective

Update BIT to work locally by default; copy example .env over to local .env then populate using the setup scripts. Devs only have to run the setup script and follow the prompts.

[github-actions]

Bitwarden Claude Code Review

Overall Assessment: APPROVE

This PR makes BIT work locally out-of-the-box by populating .env.example with sensible defaults, adding an automatic .env bootstrap step plus npm/docker compose prerequisite checks to first-time-setup.sh, and extracting setup:extension into a dedicated scripts/setup-extension.sh script. Both scripts now perform a graceful nvm install when nvm is detected. The README is updated to reflect the streamlined workflow and the move from the self-host Unified image reference to the Bitwarden Lite image.

Code Review Details

No blocking findings. The shell changes follow existing conventions (set -e, BASH_SOURCE-relative project root, graceful nvm fallbacks with || echo so set -e does not abort), and the .env.example defaults align with the Docker Compose configuration: BW_DOMAIN=127.0.0.1 matches the SSL cert SAN and the lite image reference matches the README link.

The two existing reviewer threads have been addressed:

• .env.example placeholder password concern — fixed in 064d0e7 (default password no longer contains an email-shaped value).
• first-time-setup.sh ordering of nvm install vs setup:ssl — resolved; generate-certs.sh does not require Node.