feat(atlas): UX — plain node titles + mobile transition rows (re-review #1,#2)

Lap-2 review's top two findings:
#1 Node titles were still jargon (the lap-1 disease one level down). Every node
now has a plain_t ("var-go Oath" → "Definition of done", "Admission controller"
→ "Tamper-proof seal", …); Plain view leads with it and demotes the technical
name to a dim in-card subtitle — mirrors the stage-head pattern. plain_t on every
authored node is now guard-tested.
#2 Transition labels lived only in the SVG spine (display:none <820px) with a
hover-only rationale — invisible on phones. Added stacked-layout transition rows
(HTML, always-visible, full sentence, no hover) shown on mobile; desktop header
band scoped to ≥821px so mobile isn't stretched.

build/vet/lint(0)/test green; desktop Plain screenshot-verified.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/UX-REVIEW-2.md

@@ -0,0 +1,236 @@
+# CAD Atlas — Fresh-Eyes UX Review, Lap 2
+
+Reviewer role: fresh-eyes UX (not implementer). Second pass, judging the shipped
+progressive-disclosure sprint against the goal set in `UX-REVIEW.md`. This document
+critiques; it does not change code.
+
+Sources reviewed:
+- `docs/UX-REVIEW.md` (the spec that was implemented — lap 1)
+- `internal/atlas/atlas.json` (authored data: `plain_title`, `plain`, `trans_label`,
+  `trans` per stage; `plain` per node)
+- `internal/web/static/cad-atlas.html` (the renderer: Plain⇄Technical toggle, spine
+  transition labels, legend, substrate/footer hidden in Plain)
+- `/tmp/ux5/home.png` (deployed Plain view, stages 00–04 in frame)
+
+---
+
+## 1. Verdict
+
+**The sprint largely achieved the *phase* half of the success criterion and made a real
+dent in the *transition* half — but it does not fully clear the bar. Grade for a naive
+viewer: B / B+.**
+
+Success criterion was: a viewer with no briefing can explain **every phase** AND **what
+advances work across every transition.**
+
+- **Phases: pass.** This is the big win. The headline hierarchy works — big plain_title
+  ("Notice what's happening", "Why we're here", "Agents do the work"), a dim technical
+  subtitle, and a jargon-free "what happens" sentence. A cold stakeholder can now narrate
+  every column. This is a genuine, measurable improvement over lap 1, where every column
+  was a mechanism name. Full marks here.
+
+- **Transitions: partial.** The short spine labels ("Does it matter to us?", "Worth a
+  session?", "Decision reached", "Sealed & agent-ready") convey the *gist* of each hop,
+  which is a step-change from the blank arrows of lap 1. But three things hold it back
+  from "can explain what advances work":
+  1. The actual "what must be true to advance" sentence (`trans`) is **hover-only** (an
+     SVG `<title>` tooltip). That is undiscoverable — nothing signals it's hoverable — and
+     dead on touch devices. So the naive viewer gets the one-line theme, not the gate
+     logic.
+  2. The labels are **terse and grammatically mixed**: some are questions ("Does it matter
+     to us?"), some are achieved-states ("Decision reached", "It's live"). A first-timer
+     builds two different mental models — "is this the question asked here, or the answer
+     reached?" — from one row.
+  3. **They vanish on narrow screens.** All transition labels live inside `svg.spine`,
+     which is `display:none` under 820px, and the stacked mobile layout renders no HTML
+     fallback. The single biggest comprehension win of the sprint is absent on a phone.
+
+- **The viewport undermines both.** The atlas is a 9-column horizontal scroll and a laptop
+  shows ~stages 00–03. That means **stage 04, the one human gate — the thing the header
+  literally advertises ("one human gate") — is off-screen on load**, along with execution,
+  CI, deploy, and the loop. A first-timer cannot see the shape of the gated flow, cannot
+  see that a human checkpoint exists, and gets no affordance that five more stages are to
+  the right. The atlas's whole payoff — "see the auditable flow from signal to pod at a
+  glance" — is not deliverable in the default viewport.
+
+Net: the copy layer is excellent and the toggle is the right architecture. The remaining
+gap is structural (what's visible, and where the transition rationale lives), plus one
+stubborn copy residue (node titles). A naive viewer *can* explain the phases unprompted;
+they can explain the transitions only at a slogan level, and only for the half of the
+pipeline they happen to scroll to.
+
+---
+
+## 2. What works (the genuine wins)
+
+- **Plain default + persisted toggle.** Right call, right default. Nothing was thrown
+  away; Technical is the old atlas verbatim. Architecture matches the spec.
+- **Stage headline hierarchy.** plain_title dominant, technical title demoted to a dim mono
+  subtitle, plain sentence underneath. Clean, scannable, correct visual weight.
+- **Transitions exist at all.** Even terse, the labelled arrows turn a row of boxes into a
+  narrated flow. This was the #1 lap-1 miss and it shipped in the default layer.
+- **Density dropped in Plain.** Tags, risk chips, host ribbon and footer are all suppressed
+  in Plain (`body.plain`), so the reading surface is airy and calm — a real contrast to the
+  lap-1 wall of pills.
+- **Stage 06 no longer reads as empty.** An authored "Automated checks" node with plain copy
+  now backstops the live CI generation, so the CI gate never looks like a no-op on a cold
+  load. Directly fixes lap-1 punch-item 7.
+- **Feedback bus is honestly hedged.** Dashed violet + "partly manual today" in both the loop
+  label and the legend. Matches the dogfooding-honesty discipline.
+- **The pulse gives direction.** The travelling dot is a low-cost "this flows left-to-right,
+  then loops back" cue — helpful for orientation.
+
+---
+
+## 3. What's still weak (shipped Plain view)
+
+**a. Node titles are still pure mechanism-jargon — the exact lap-1 disease, one level down.**
+The node *body* is now plain, but the node *title* — the first, boldest thing the eye lands
+on in a card — is untouched: "Applied AI Radar", "Intention substrate", "Admission
+controller", "var-go Oath", "Session-Dispatch bridge", "Executor + reviewer loop",
+"dma-cli · routing + scope", "assessor-loop ledger". The plain body can't fully rescue a
+card whose title already framed it as a mechanism. The stage head got the plain-title/tech-
+subtitle treatment; the node did **not** — an inconsistency that leaves each column half-
+translated. See §4.
+
+**b. The transition rationale is hidden and fragile.** As in §1: `trans` is hover-only
+(undiscoverable, touch-dead) and the whole label layer disappears under 820px. The "what
+must be true to advance" — the governance content the atlas exists to show — is the least
+robustly delivered part of the whole thing.
+
+**c. Horizontal scroll with no affordance = half the pipeline is invisible.** Nothing at the
+right edge signals "more stages this way" — no fade, no scrollbar cue, no "→ 04–08", no
+overview. A first-timer may reasonably believe the pipeline is five stages that end at "Write
+the work order". The marquee human gate and the entire execute→ship→loop arc are off-frame by
+default. This is the single largest comprehension barrier remaining.
+
+**d. Transition-label attachment is weaker than specced.** Lap-1 §5 asked for **label chips
+sitting on the spine**; what shipped is floating 10px mono text ~9px above the arrow with no
+background. On the dark grid it reads, but it floats — the viewer has to mentally bind the
+text to the arrow beneath it. A chip (or a short leader) would make the label read as *of*
+the arrow, not near it.
+
+**e. Gate treatment is cryptic.** Lap-1 §5 asked for a lock/shield glyph + stronger colour on
+the two real gates (04 human, 06 CI). What shipped is a "▸ " prefix + gold + bold on those two
+labels. A naive viewer will not read "▸" as "governance checkpoint"; the only real cue is
+"one of these labels is gold", which leans entirely on the legend. The two most important hops
+in the whole atlas deserve a glyph that says *stop / check*, not an arrowhead character.
+
+**f. The legend doesn't match the colours actually on screen.** The KEY decodes green/amber/
+coral as CI run-states plus gold=gate + dashed=feedback. But in Plain the cards show **violet,
+blue, and coral pills** and **coloured/dashed borders** (council=violet, bridge=dashed-blue,
+oath=dashed-gold, executor=coral) that the KEY never explains — while the green/amber/coral CI
+states the KEY *does* explain are barely present in Plain. So the viewer sees a violet dot on
+"Intention substrate" and a dashed-gold box on "var-go Oath" with no way to decode them, and a
+legend describing states they can't see. Colour is carrying two unrelated meanings (authored
+semantics vs. live CI status) under one key. Either key every colour/border shown in Plain, or
+strip the decorative pills/borders in Plain so colour means only what the legend says.
+
+**g. The technical subtitle is a wash — mild noise, mild help.** Under the plain_title sits
+`s.title`: sometimes near-plain ("Signals", "Strategic session"), sometimes pure jargon
+("TELOS", "Spec → Gitea issue", "PR → CI", "Execute · agentsquad"). For a naive viewer roughly
+half of these subtitles are undecodable filler directly under the headline; for a new engineer
+they're a useful canonical-name bridge without a mode-switch. Because it's dim and small the
+noise cost is low, so **keep it** — but note the *inconsistency*: the stage trusts the reader
+with a dim technical name under a plain headline, yet the node doesn't extend that same courtesy
+(§4). Apply the pattern uniformly.
+
+**h. Unexplained accent colours on headlines.** plain_title is violet for TELOS/Loop and amber
+for the gate. Meaningful to the author, unkeyed for the viewer — a minor echo of problem (f).
+
+**i. The feedback bus reads as a mystery line in-viewport.** The dashed violet return leg drops
+straight down out of the TELOS column, but its label ("What did we learn? · feedback bus")
+sits at the very bottom of a 9-column-wide canvas — off-screen for anyone who hasn't scrolled
+down and right. In the default view you see an unexplained dashed vertical line and no origin
+(stage 08 is off-frame right). The honesty hedge is good; the *legibility* of the loop in the
+first screen is poor.
+
+---
+
+## 4. Node-title question — recommendation: **add plain node titles; keep the technical name as a dim subtitle inside the card.**
+
+Do **not** keep titles as-is, and do **not** simply swap in plain titles and delete the
+technical ones. Mirror the pattern the stage head already uses, one level down:
+
+```
+[pill] Marks its own homework? No.          ← plain_t  (bold, primary)
+       Executor + reviewer loop             ← t        (dim mono subtitle)
+       One agent does the work; a second,   ← plain    (body, already shipped)
+       independent agent reviews it …
+```
+
+Reasoning for the mixed audience:
+
+- **The title is the frame.** The eye reads title → body. A jargon title ("Admission
+  controller", "var-go Oath") sets a mechanism frame that a plain body then fights against.
+  This is precisely the lap-1 diagnosis ("every node names a *mechanism* rather than the
+  *thing that happens to the work*") — it was fixed for stages and bodies but left standing in
+  node titles. The job is half-done until titles get the same treatment.
+- **A naive viewer needs the plain title.** "Marks its own homework? No.", "Signed so tampering
+  shows", "The one human yes/no", "A machine-checkable definition of done" — these are
+  explainable at a glance; "dma-cli · routing + scope" is not.
+- **A new engineer still needs the canonical name.** "var-go Oath", "Ed25519 admission
+  controller", "assessor-loop ledger" are the searchable terms that connect the picture to the
+  code and the brain. Deleting them would help the stakeholder and hurt the engineer — the
+  wrong trade for a "everyone" audience.
+- **Consistency is its own win.** Right now stage heads say "plain big / technical small" and
+  nodes say "technical only". Two rules for the same card type is friction. One rule, applied
+  at both levels, makes the whole atlas feel like one designed system and makes the toggle's
+  mental model ("plain names up front, mechanisms one layer in") coherent.
+
+Concretely: add an optional `plain_t` per node in `atlas.json`; in Plain render `plain_t` as
+the title and `t` as a `tech-sub`-style dim line (reuse the existing class); in Technical keep
+today's behaviour (`t` as title). Nodes without a `plain_t` fall back to `t`, so it's an
+incremental authoring task, not a big-bang rewrite.
+
+---
+
+## 5. Prioritized next punch list (top 6 by comprehension impact)
+
+1. **Add plain node titles (`plain_t`), technical name demoted to a dim in-card subtitle.**
+   Highest impact: the title is the first thing read and it's still the lap-1 jargon disease.
+   Finishes the progressive-disclosure job the stages already got. (§3a, §4)
+
+2. **Solve the horizontal-scroll blindness.** A first-timer must be able to tell the pipeline
+   is nine stages and reach the human gate and the loop. Ship at least a right-edge fade +
+   "→ stages 04–08" hint; ideally a "fit to width / overview" zoom toggle so the whole gated
+   shape (and the one human gate the header promises) is visible at a glance. (§3c)
+
+3. **Render transition labels in the stacked/narrow layout, and surface the `trans` sentence
+   without a hover.** The labels currently die under 820px (they live only in the SVG) and the
+   gate rationale is hover-only/touch-dead. Emit `trans_label` as an HTML element between
+   stacked stages, and make the full `trans` reachable by click/tap (expandable), not just
+   desktop hover. This is the "explain every transition" half of the success criterion. (§1, §3b)
+
+4. **Give the two governance gates (04 human, 06 CI) a real glyph and make the feedback loop
+   legible in-viewport.** Replace the "▸" prefix with a lock/shield on the gold gate labels so
+   the checkpoints read as checkpoints; and attach a visible "What did we learn?" chip to the
+   top of the feedback return leg near TELOS so the dashed line isn't a mystery in the first
+   screen. (§3e, §3i)
+
+5. **Reconcile the legend with the colours on screen in Plain.** Either key every pill/border
+   meaning the Plain view shows (violet/blue/coral pills; council/bridge/oath borders) or drop
+   the decorative pills/borders in Plain so colour means only the CI states the KEY describes.
+   Today the legend and the canvas disagree. (§3f, §3h)
+
+6. **Turn floating transition text into attached chips and normalise the grammar.** Give each
+   label a small chip background so it reads as *on* the arrow, and pick one voice — all
+   "what-must-be-true" states ("Mattered to us", "Decision reached", "Human said go", "All
+   checks green", "It's live") reads more consistently than mixing questions and states. (§3d)
+
+---
+
+### Scorecard vs. lap-1 punch list
+
+| Lap-1 item | Status |
+|---|---|
+| 1. Label every arrow | **Shipped** (desktop only; hover-only rationale; dies on mobile) |
+| 2. plain_what per stage + demoted title | **Shipped** — clean |
+| 3. Plain⇄Technical toggle, default Plain, persisted | **Shipped** — correct |
+| 4. Plain node primary text, `d` on demand | **Half** — bodies plain, **titles still jargon** (§4) |
+| 5. Distinguish the two gates (lock/shield) | **Weak** — "▸"+gold, no glyph |
+| 6. Legend keying colours + gate types | **Partial** — legend exists but doesn't match Plain colours |
+| 7. Fix stage-06 empty column | **Shipped** — authored fallback node |
+| 8. Honest feedback bus + suppress proper nouns in Plain | **Half** — bus honest; proper nouns still leak via node titles + tech-subs |
+</content>
+</invoke>