Publish the documentation site: docs.fluksio.com

A zensical site under docs/, served by a new `docs` compose service behind
Traefik, built with --strict in CI. Same pattern the sibling n3xd workspace
uses.

Getting started splits the way the landing page does — one path is
`pip install fluksio` and a training script, the other is a Docker stack and
an afternoon in the browser — because the two audiences will not spend the same
amount of time. Everything after that is shared: the concepts, the web
interface (app and portal), the CLI and the API, and a reference for node types,
payload types and configuration.

The three flow guides move here from the docs submodule rather than being
copied, so there is one version of them.

Styling mirrors DESIGN-GUIDELINES.md: the app's token palette remapped onto
Material's variables in both schemes, Inter, the 16px panel radius, and the one
terracotta accent spent on the facility lane of the audience split.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M7Xv3cJEW5c8AXxn2hoojV

docs/interface/index.md

@@ -0,0 +1,88 @@
+# The dashboard app
+
+The web interface is a single-page app served at `app.${DOMAIN}` — or, for an
+installation reached through a portal, at `${DOMAIN}/i/{installation-id}`.
+Either way it is the same application, and it is a client of the same REST API
+you can script against.
+
+Sign in with the account the installation was created with. On a fresh
+installation that account was printed once, on the first start.
+
+## The shell
+
+A floating sidebar on the left, the selected screen filling the rest. On a
+phone the sidebar collapses to a sheet.
+
+| Entry | What lives there |
+|---|---|
+| **Home** | the brain graph, health, and everything that recently happened |
+| **Flows** | the list of flows, and the canvas for each |
+| **Dashboards** | the widget canvases, and the panels that display them |
+| **Secrets** | credentials your nodes reference without holding |
+| **Modules** | the Python packages your node code may import |
+| **Alerts** | where failures get sent |
+| **Admin** | users (superusers only) |
+| **Settings** | your account, appearance, and remote access |
+
+## Home
+
+The one screen you leave open. Three things share it.
+
+### The brain graph
+
+Every flow drawn as a neuron, wired to the flows it exchanges messages with.
+This is the brand mark made live, and it is also the fastest read on the
+installation: a neuron pulses when its flow is running work, and its ring turns
+terracotta when the flow cannot run as written. A neuron with a problem keeps
+its label showing so you can see which one it is without hovering.
+
+Each flow also has a switch beside it in the list, which starts and stops it.
+
+### Health
+
+Always answers, degraded or not. The tiles cover:
+
+- **Flows** — total, running, paused, quarantined, and how many cannot run
+  because their graph does not validate
+- **Nodes** — how many failed to load
+- **Queue** — depth, and how old the oldest pending item is
+- **Loop lag** — whether the engine's event loop is keeping up
+
+`status: degraded` comes with a list of named problems, in words. "3 flow(s)
+cannot run: house, pv, hallway" is more useful than a red dot, so that is what
+it says.
+
+### Activity
+
+Charts of executions and failures over the selected range (1h / 6h / 24h / 7d),
+with the recent runs, recent failures, dead-lettered work and the audit trail
+underneath.
+
+The charts are scrubbable: hover a moment and the lists below filter to it,
+click to hold it while you read. That turns "something went wrong around two
+o'clock" into the actual rows.
+
+## Flows
+
+The list shows each flow's title, node count, whether it has unpublished
+changes, and whether it is enabled, paused or quarantined. The toolbar searches,
+creates, and offers **Publish all changes** when several flows have drafts.
+
+Opening one takes you to [the flow editor](flow-editor.md).
+
+## Everything else
+
+- [The flow editor](flow-editor.md) — the canvas, the code editor, running and
+  testing
+- [Dashboards and panels](dashboards.md) — widgets, bindings, and hanging a
+  screen on a wall
+- [Secrets, modules and alerts](operations.md) — the three screens that keep an
+  installation running
+- [Accounts and the portal](portal.md) — reaching an installation from outside
+  its network
+
+## Appearance
+
+Light and dark follow your system by default; **Settings → Appearance**
+overrides it. Both themes are first-class — the wall-panel view in particular is
+designed to be legible in dark from across a room.