Demo that looks like a real array, and the README pictures from it

[firsttris]

So far the README and documentation pictures came from a hand-made state: 4 disks of 2–16 TB, last sync 10 hours ago, scrub at 64 %, schedules. The demo (./start.sh --demo) showed tiny KiB disks, the host's free space and no history.

Demo mode (SNAPRAID_DEMO=1, backend/src/demo.ts)

• status: the real log of the sandbox, with the sizes, file counts and fragmentation of the demo disks and a scrub that keeps up (64 %, oldest block 17 days). Paths and content files stay as SnapRAID reports them, so the disk check works as before.
• Disk usage (df) and the parity file's size: the same demo disks instead of the host's filesystem.
• Disk profiles: the data disks get the profiles they already had for SMART. Parity gets its own 18 TB profile, so it is the largest disk.
• Docker: three demo containers (immich, jellyfin, nextcloud) that can be paused and resumed, so the Automation page works without Docker.

Sandbox (dev/setup.sh, dev/seed-demo.ts)

• "Media Array" with disk1–disk4 and parity1.
• Real runs of sync, scrub, touch, sync, diff and status, with logs. seed-demo.ts moves the logs back in time: last sync 10 hours ago, scrub yesterday.
• Two months of usage-history.json with disk3 filling up ("full in about 153 days").
• Three schedules: nightly sync with touch and scrub, weekly scrub, SMART check.
• maintenance.json with Docker pause and spindown.
• DISKS_DIR=/mnt puts the disks at /mnt/disk1, as in the pictures. Safety: every sandbox disk carries a marker file. setup.sh refuses to touch a directory that is neither empty nor marked, so a real /mnt/disk1 is never removed or filled. I tested this with a directory holding foreign data.

Pictures

• e2e/screenshots/readme.spec.ts with playwright.screenshots.config.ts and harness/demo-setup.ts: builds a fresh sandbox, the frontend, and the backend in demo mode behind the e2e proxy.
• It takes 10 pictures: dashboard light, dark and phone, command palette, SMART, logs, schedules, notifications, automation, social preview.
• Run it with npm run screenshots in e2e/.
• Update screenshots (.github/workflows/screenshots.yml, started by hand) runs it in the Playwright image via firsttris/workflows (playwright-image, commit-changes) and commits what changed.
• docs/screenshots/daemon.png stays hand-made: it needs two reachable snapraid-daemon instances.

Checked locally

• deno check passes and all 125 backend tests pass, including new tests for the demo status, disk usage and Docker.
• npm run typecheck in e2e/ passes, actionlint and shellcheck pass.
• A full run from a fresh sandbox at /mnt: all 10 pictures, which match the current ones in structure. They are not part of this PR; the workflow takes them in the fixed image after the merge.
• Docs: development (demo sandbox, new "Screenshots" section), configuration and architecture.

🤖 Generated with Claude Code

https://claude.ai/code/session_01HPLSH4GpJHjeKdjRBDuN9s

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Generated by Claude Code