Computed flow layout, and mobile written into the design

The canvas lays itself out: a layered graph, left to right on a desktop and
top to bottom on a phone, with room reserved for the value each edge carries.
Nodes cannot be dragged and `NodeDef.position` is gone from the document —
a graph nobody can arrange is one worth keeping small, which is what keeps
flows atomic. Endpoints join the same layout, so their lanes and the
localStorage that remembered where they were dragged go too.

Mobile, per the new Responsive section of DESIGN-GUIDELINES.md: the dock caps
its width and wraps instead of running off the screen, the dashboard stacks
into one column rather than shrinking a wall panel to a fifth of its size, and
Home stops widening its grid track past the viewport. A Playwright project at
a phone's width fails the build when a screen no longer fits.

Along the way: publish is the checkmark that was already there rather than a
button that appears and disappears, with discard beside it on both the flow
and the dashboard; the brain reveals a neuron's name on the first tap; and the
port sparklines get room to breathe.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VDSXaRhvqHYNevgDGmNAto

NOTEPAD.md

@@ -13,19 +13,21 @@ should reopen it.
 
 ### To be sorted
 
+- BUG/UI dots and rings of nodes in the brain graph are not pixel-perfect centered
+- BUG/UI rings of ndoes in the brain graph should be come a bit thinner and edges a bit thicker. Also ensure that trigger animations of nodes are still visible. We could use make the ring pulse instead of the existing effect
+- BUG/UI HEALTH section shows 1 flow(s) cannot run but boxes below show e.g. 5/5 flows running
+- FEAT/UI we should highlight failing nodes accordingly in the flow view
 - BUG/UI when a dashboard widget is selectd, the border does not cleanly draw on the left side of the widget
-- BUG/UI there is currently no option to discard changes (in dashboard or flow viewport); we should make add a "X" button to discard and replace "Publish" by the already existing checkmark button which is either clickable when there are unpublished changes or unclickable when the changes have been applied (but the icon stays). The discard button should only show when there are changes (hidden else)
 - INFRA: ensure that all the packages/ dependencies needed to run fluksio are available on arm to make this software runnable on e.g. raspbian
 - INFRA: merge the philosophy statement at the beginning of vision.md into the rest of the document. Dissolve the decision dates and fold the decisions into a clean structure
-- BUG/UI mobile friendly support is degraded: 1) toolbar in the "Flows" viewport extend mobile viewport width 2) position of nodes should never be static (holds true for desktop as well); always adjust such that there are as few as possible overlaps (of nodes and edge labels) and direction is left to right (desktop) or top to bottom (mobile) with a minimal (but clean) overall edge length. This should also remove the ability to drag nodes around; their position is fixed by an algorithm. This design choice is what enforces small atomic flows (different from nodered) 3) Dashboard view is not mobile friendly at all; as dashboard design is infeasible on mobile, render all widgets in a vertically stacked order. This allows to inspect each widget and make changes. Layout changes are not a feature on mobile 4) the home view is not responsive; all items shown there should re-order on mobile such that no scrollbars appear. Make sure the mobile support is anchored in the design such that future work does not break it
 - FEAT/UI add a loading animation for the initial app load and when loading individual pages; make sure that elements e.g. in the home dashboard load independently to ensure a fast loading of the initial site but figures charts, tables, graph etc. follow after that
 - FEAT/UI introduce a graph panel which renders at the top right next to the graph view (to make more use of the horizontal space) and which allows (de-) selecting flows to be excluded from the graph view or search for individual nodes where only the flows containing this node should be shown (like slicing the brain)
 - FEAT/UI durations are written as a shortened number beside a fixed unit, so a slow run reads "1.2k ms" rather than "1.2 s". A duration formatter that steps the unit itself (µs/ms/s/min) would read better wherever `si` is followed by "ms"
-- CHORE/UI `biome check ./src` reports an ineffective suppression at `FlowEditor.tsx:473` (`useExhaustiveDependencies` no longer fires there)
 - FEAT/UI the brain's activity falloff is session-observed: a page just opened shows every neuron and connection at the same neutral base, and only sorts itself out as values arrive. A "last published" timestamp per node from the backend would let it open already sorted.
-- CHORE/UI the brain's hover labels have no touch equivalent — a tap navigates to the flow, and there is no hover to reveal a name first. The native `title` carries it on desktop only.
-- BUG/UI slightly increase the margin between the top of a graph in the node/flow panel and the consumer/producer field
 - FEAT/UI labels in flows (indicating dashboard widget connections) naturally can't pulse. Instead add an animation (enlightning fade) from either ltr or rtl depending if the label is in- or outbound
+- CHORE/UI: `layoutGraph` treats every node as 220×56 rather than measuring, because feeding a measurement back into the layout oscillates. A node wider than that crowds its neighbours; take the sizes from `node.measured` once they have settled if it shows.
+- FEAT/UI/MOBILE: a rank of many nodes — a connector feeding eight dashboard tiles — is thousands of pixels wide however the graph is turned, so on a phone the fit shrinks it past reading. The layout is right and the flow is simply too big for the screen; a "one rank at a time" reading mode, or wrapping a wide rank, is what would make it legible.
+- CHORE/UI: an edge's value chip sits at the bezier midpoint while the layout reserves its room at dagre's label rank. The two agree closely enough today; if chips ever pile up, take the position from the layout instead.
 - FEAT/UI (deferred until MCP lands): add a "bot" icon button to the home view (graph panel) which opens a chat window (reuse general concept of a side panel like in flows/nodes to make it a chat panel which can open on any screen (stacks below any other existing panel -> introduce stacking) to give support on errors/write code, generate dashboards etc) to explain the error(s)
 
 ### Persistence and databases
@@ -163,10 +165,9 @@ as an em dash.
 - CHORE/UX: dropping a widget also selects it, which opens its panel — which rescales the canvas the instant you let go. Correct, but it lurches; either leave the panel closed on a drag-release or animate the scale.
 - CHORE/UI: `ROW_HEIGHT` is a fixed 80px while column width follows the canvas, so a 1920-wide panel at 12 columns has 160×80 cells. If that reads too wide, the row height could derive from the canvas too.
 - FEAT/UI: multi-page and multi-section dashboards have no UI. The backend has `PageDef`/`SectionDef` and rename; the editor only ever edits `sectionsOf(page)[0]`, so nothing can create a second page.
-- FEAT/UI: only `layout.lg` is ever written. Below `lg` the view stacks widgets full width in CSS, so `md`/`sm` stay unused until a per-breakpoint editor exists.
+- CHORE/UI: only `layout.lg` is ever written, and `md`/`sm` stay unwritten by decision — a phone stacks the widgets (`.widget-stacked`) rather than carrying an arrangement of its own, since arranging is not a phone feature. The keys stay in the schema for a panel that one day wants a second size.
 - PERF/UI: `ChartWidget` re-joins the whole table on every live value. Fine at IoT rates; at `HISTORY_CAP` × 5 series it should append into a ring buffer.
 - CHORE/UI: opening edit mode on a dashboard whose widgets predate placement writes the migrated positions immediately, bumping the version once.
-- FEAT/UI: `POST /dashboards/{name}/discard` has no button. The flow settings panel offers "discard draft"; the dashboard settings panel does not, so an unwanted edit can only be undone by hand or by publishing it.
 - CHORE/API: creating a dashboard publishes it straight away (an empty document goes to the panels), while a new flow starts as a draft. Keeps `read`/`list` free of a never-published case, at the cost of the asymmetry.
 - PERF/UI: "Publish all" reads each document's detail for the version its publish must match, so a click is 2N requests. A bulk endpoint, or a `version` on the summaries, would make it one.
 
@@ -208,7 +209,6 @@ Open on purpose. Each names what should bring it back.
 - CHORE/FLOW: shared node sources bypass the draft/publish split. Editing one writes the library copy and reloads immediately, since the code is not any single flow's to hold back. Deliberate, but it means a shared node is the one thing publish does not gate.
 - CHORE/INFRA: `requires-python` is capped below 3.14 because the MCP SDK wants a newer starlette there than the pinned `sentry-sdk<2` allows. Lift the cap when sentry-sdk moves to 2.x.
 - CHORE/INFRA: `bun run --filter frontend build` fails on this workspace with `crypto.hash is not a function` — Vite 7 wants Node 20.12+ and the host has 18. The Docker image builds fine, so it only bites local bundling; `bunx tsc` still type-checks.
-- FEAT/UI: an endpoint's edge routes straight across the graph, so it can pass behind a node that sits between the lane and the node it wires to. Readable, but a routed edge would be tidier.
 - FEAT/UI: the node-panel and edge trend curves take no range, unlike the health block. They are drawn from a Redis ring of the last 120 values per message, which has no window to ask for — a hover caption names what the curve covers instead of a picker promising a span nothing can serve. Reopen if per-message history ever gains a time window.
 - FEAT/UI: an e-ink rendering profile for a dashboard — motion off, hover-only affordances resolved to something visible, high-contrast palette, thick strokes, and a repaint cadence low enough for a display that takes a second to settle. Reopen when a panel with such a display is actually hung.
 - CHORE/INFRA: Postgres stays. The 2026-08 review rejected YugabyteDB/CockroachDB (multi-node cluster systems, ~4 GB+ RAM per node, against the small-server target — the scaling story is remote workers, not a distributed DB) and found merging Postgres into Redis or vice versa buys little: the stores hold disjoint data and both sit behind abstractions. SQLite would fit the single-instance design and drop a container; reopen if the home-install footprint becomes a product concern.