feat(atlas): Phase B — data-driven /api/atlas.json, CI stage generated from cd.yml

The atlas no longer hand-maintains its content. Authored data lives in one place
(internal/atlas/atlas.json); the Go layer overlays sourced facts and serves the
result at /api/atlas.json; the frontend fetches + renders (inline arrays kept only
as an offline fallback). First generated source: the CI/CD stage's nodes are parsed
from the repo's own .gitea/workflows/cd.yml — so the viz shows the pipeline that
actually runs (guard/check/build/deploy), dropping the aspirational var-go/oath-gate
node that isn't wired yet. That's the point: it can't drift from the real pipeline.

New internal/atlas package (JobsFromWorkflow, Build) built test-first. Adds
gopkg.in/yaml.v3 (justified: parsing the workflow YAML; stdlib has no YAML).

Verified: go build/vet/lint(0)/test green; /api/atlas.json → 9 stages, CI = real
jobs; frontend renders from the fetch (screenshot).

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

internal/web/handler.go

@@ -1,20 +1,22 @@
 package web
 
 import (
-	"context"
 	_ "embed"
+	"encoding/json"
 	"net/http"
+
+	cadatlas "git.d-ma.be/mathias/cad-atlas"
+	"git.d-ma.be/mathias/cad-atlas/internal/atlas"
 )
 
-// atlasHTML is the Phase-A static hero visualization. Phase C replaces this
-// self-contained file with a Templ view hydrated from live CAD trace data
-// (assessor-loop ledger, session_log, Gitea run API, Flux events).
+// atlasHTML is the Phase-A/B static shell. It fetches /api/atlas.json at load
+// and renders from that data (no inline arrays), so the content is sourced.
 //
 //go:embed static/cad-atlas.html
 var atlasHTML []byte
 
-// NewHandler serves the CAD Atlas. Root ("/") returns the static atlas;
-// /api/hello is a leftover template probe kept until Phase C wires real endpoints.
+// NewHandler serves the CAD Atlas: the shell at "/", and the sourced data at
+// "/api/atlas.json" (authored data + CI stage generated from the real cd.yml).
 func NewHandler() http.Handler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
@@ -25,8 +27,14 @@ func NewHandler() http.Handler {
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
 		_, _ = w.Write(atlasHTML)
 	})
-	mux.HandleFunc("/api/hello", func(w http.ResponseWriter, r *http.Request) {
-		_ = Hello("world").Render(context.Background(), w)
+	mux.HandleFunc("/api/atlas.json", func(w http.ResponseWriter, r *http.Request) {
+		a, err := atlas.Default(cadatlas.CDWorkflow)
+		if err != nil {
+			http.Error(w, "atlas build failed", http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		_ = json.NewEncoder(w).Encode(a)
 	})
 	return mux
 }

internal/web/handler_test.go

@@ -1,10 +1,13 @@
 package web
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"strings"
 	"testing"
+
+	"git.d-ma.be/mathias/cad-atlas/internal/atlas"
 )
 
 func TestRootServesAtlas(t *testing.T) {
@@ -27,6 +30,43 @@ func TestRootServesAtlas(t *testing.T) {
 	}
 }
 
+func TestAtlasJSON_ServesAtlasWithGeneratedCIStage(t *testing.T) {
+	srv := httptest.NewServer(NewHandler())
+	defer srv.Close()
+
+	resp, err := http.Get(srv.URL + "/api/atlas.json")
+	if err != nil {
+		t.Fatalf("GET /api/atlas.json: %v", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("status = %d, want 200", resp.StatusCode)
+	}
+	var a atlas.Atlas
+	if err := json.NewDecoder(resp.Body).Decode(&a); err != nil {
+		t.Fatalf("decode atlas: %v", err)
+	}
+	if len(a.Stages) == 0 {
+		t.Fatal("atlas has no stages")
+	}
+
+	// The generate:ci-jobs stage must be populated from the real cd.yml jobs.
+	got := map[string]bool{}
+	for _, s := range a.Stages {
+		if s.No == "STAGE 06" {
+			for _, n := range s.Nodes {
+				got[n.Title] = true
+			}
+		}
+	}
+	for _, want := range []string{"guard", "check", "build", "deploy"} {
+		if !got[want] {
+			t.Fatalf("CI stage missing generated job %q (got %v)", want, got)
+		}
+	}
+}
+
 func TestUnknownPath404(t *testing.T) {
 	srv := httptest.NewServer(NewHandler())
 	defer srv.Close()

internal/web/static/cad-atlas.html

@@ -114,7 +114,7 @@
 <body>
 <header>
   <h1><b>CAD</b> Atlas · From Signal to Pod</h1>
-  <span class="sub mono">one human gate · everything up- and downstream is agents · <em>v0.3 static snapshot (→ live in Phase C)</em></span>
+  <span class="sub mono">one human gate · everything up- and downstream is agents · <em>v0.4 · data-driven (CI stage generated from cd.yml)</em></span>
   <div class="controls">
     <button id="replay"><span class="dot"></span> Replay</button>
     <button id="slowmo">Slow-mo · <span id="slowState">off</span></button>
@@ -145,20 +145,22 @@
 <footer class="mono">
   CAD → CI → CD · intent→specify→dispatch · build→test→validate · deploy→ship.
   Dashed violet = feedback bus (stage 08 → TELOS: deploy outcome scored vs originating goal).
-  Data: static inventory from <code>brain</code> (2026-07-19). Phase C swaps these arrays for live reads of
-  <code>assessor-loop</code> ledger · <code>session_log</code> · Gitea run API · Flux events.
+  Data served from <code>/api/atlas.json</code> (authored <code>atlas.json</code> + CI stage generated from the live <code>cd.yml</code>).
+  Phase C plugs in live reads of <code>assessor-loop</code> ledger · <code>session_log</code> · Gitea run API · Flux events.
 </footer>
 
 <script>
-const SUBSTRATE=[
+// Inline data is an offline FALLBACK. Authoritative data is fetched from
+// /api/atlas.json (authored atlas.json + CI stage generated from the real cd.yml).
+let SUBSTRATE=[
   {n:"koala",  k:"RTX 5070 · k3s control-plane · Gitea · LiteLLM :30401 · llama-swap :31234 · searxng"},
   {n:"iguana", k:"M2 Ultra · Ollama / mlx"},
   {n:"flamingo",k:"daily driver · ~/dev"},
   {n:"piguard",k:"NGINX reverse-proxy · ntfy"},
 ];
-const NS="Tailscale mesh · ns: ai-stack · supervisor(→brain) · gitea-mcp · infra-mcp · council";
+let NS="Tailscale mesh · ns: ai-stack · supervisor(→brain) · gitea-mcp · infra-mcp · council";
 
-const STAGES=[
+let STAGES=[
  {no:"STAGE 00",cls:"",title:"Signals",path:"→ mathias/signals",nodes:[
    {t:"Applied AI Radar",d:"Daily Tier-1 + weekly Tier-2 deep pass. Verified-primary bar (paper/benchmark/code/named-lab).",tags:["cron · daily/weekly","→ signals #1–26+"]},
    {t:"Manual capture",d:"claude.ai strategic drop · brain capture tool.",tags:["ad-hoc"]},
@@ -200,14 +202,17 @@ const STAGES=[
  ]},
 ];
 
-const sub=document.getElementById('substrate');
-SUBSTRATE.forEach(h=>{const el=document.createElement('div');el.className='host';
-  el.innerHTML=`<b>${h.n}</b><span class="k mono">${h.k}</span>`;sub.appendChild(el);});
-const mesh=document.createElement('div');mesh.className='host mesh mono';mesh.textContent=NS;sub.appendChild(mesh);
-
 const track=document.getElementById('track');
-const stageEls=[];
-STAGES.forEach(s=>{
+let stageEls=[];
+function renderAtlas(){
+  const sub=document.getElementById('substrate');
+  sub.querySelectorAll('.host').forEach(el=>el.remove());
+  SUBSTRATE.forEach(h=>{const el=document.createElement('div');el.className='host';
+    el.innerHTML=`<b>${h.n}</b><span class="k mono">${h.k}</span>`;sub.appendChild(el);});
+  const mesh=document.createElement('div');mesh.className='host mesh mono';mesh.textContent=NS;sub.appendChild(mesh);
+  stageEls=[];
+  track.querySelectorAll('.stage').forEach(el=>el.remove());
+  STAGES.forEach(s=>{
   const st=document.createElement('div');st.className='stage '+s.cls;
   let h=`<div class="no mono">${s.no}</div><h2>${s.title}</h2><div class="path mono">${s.path||''}</div>`;
   s.nodes.forEach(n=>{
@@ -219,7 +224,8 @@ STAGES.forEach(s=>{
     h+=`<div class="node ${n.cls||''}">${inner}</div>`;
   });
   st.innerHTML=h;track.appendChild(st);stageEls.push(st);
-});
+  });
+}
 
 /* ---- geometry ---- */
 const spine=document.getElementById('spine'), spinePath=document.getElementById('spinePath'),
@@ -265,8 +271,19 @@ document.getElementById('replay').onclick=replay;
 document.getElementById('slowmo').onclick=e=>{slow=!slow;e.currentTarget.classList.toggle('on',slow);
   document.getElementById('slowState').textContent=slow?'on':'off';replay();};
 window.addEventListener('resize',()=>{clearTimeout(window._r);window._r=setTimeout(replay,150);});
-window.addEventListener('load',replay);
-build();
+async function init(){
+  try{
+    const r=await fetch('/api/atlas.json');
+    if(!r.ok) throw new Error('atlas.json '+r.status);
+    const data=await r.json();
+    if(Array.isArray(data.substrate)) SUBSTRATE=data.substrate;
+    if(typeof data.ns==='string') NS=data.ns;
+    if(Array.isArray(data.stages)) STAGES=data.stages;
+  }catch(e){ console.warn('atlas: using inline fallback —',e); }
+  renderAtlas();
+  replay();
+}
+window.addEventListener('load',init);
 </script>
 </body>
 </html>