Add plugin entry: server-status

[xMinor-1]

What the plugin does

Adds a server health indicator to the bb sidebar footer. A ring around the
button tracks RAM usage on the machine running bb — muted below 80%, amber from
80%, red above 90%, refreshed every five seconds. Clicking the button opens a
panel with the CPU and its core count, memory, swap (with a plain-language
warning once memory is being pushed to disk), disk usage for a configurable
mount point, load average over 1/5/15 minutes, uptime with the date of the last
boot, and the OS and kernel version.

Metrics are read straight from the kernel — /proc/stat, /proc/meminfo,
statfs, /etc/os-release — with no dependencies and no shelling out. One
background service polls every five seconds for the whole server and serves the
snapshot over a single state RPC method, so cost does not grow with the number
of open tabs.

Source release

• git: https://github.com/xMinor-1/bb-plugins.git
• subdir: plugins/server-status
• tagPrefix: server-status/, range: ^0.1.0
• Released tag: server-status/v0.1.0 → commit 4bff05a145db24d3457cb541f37aa70e420f0c23

Plugin checks

• npx tsc --noEmit — clean
• bb plugin build . — builds dist/server.js, dist/app.js, dist/app.css and their meta
• Engines declared by the manifest: bb >=0.39, bbPluginSdk >=0.4.8

Marketplace checks

• npm ci --ignore-scripts, npm run build, npm run check — all pass, 64 entries
• Icon vendored to icons/server-status-0fe86d02.svg (290 bytes, no scripts, no remote references)

Permissions and security

Read-only, local, and host-only. The plugin reads /proc/stat, /proc/meminfo
and /etc/os-release, calls statfs on one mount point, and uses Node's os
module. It makes no network calls, writes nothing, and runs no external
commands. The only setting is diskPath, the mount point to report on.

The frontend adds its own <svg> inside the host footer button and its panel to
document.body; nodes it does not own are never moved or removed, and
everything it creates is torn down by its disposer.