otel: wire /otel into the SPA (dual-mode SX + sx-trigger poll refresh)

lib/host/otel.sx

@@ -481,13 +481,13 @@
           (traces (otel/recent-traces)))
       (quasiquote
         (div :id "otel-dashboard"
-          ;; The host serves single-body responses (no server-push SSE), so the
-          ;; dashboard stays live by reloading itself — every 3s it re-renders the
-          ;; latest metrics + trace. /otel/stream remains a snapshot of the newest
-          ;; span for any client that wants to poll it.
-          (meta :http-equiv "refresh" :content "3")
+          ;; SPA-native live refresh: the SX engine polls GET /otel every 3s and
+          ;; swaps this div in place (outerHTML). The poll is a boosted request, so
+          ;; the route returns the text/sx fragment — no full reload, stays in the
+          ;; SPA. (No <meta refresh>, which would blow away the SPA shell.)
+          :sx-get "/otel" :sx-trigger "every 3s" :sx-target "#otel-dashboard" :sx-swap "outerHTML"
           (h1 "OpenTelemetry")
-          (p :style "font-size:0.8em;opacity:0.7" "live · auto-refreshes every 3s")
+          (p :style "font-size:0.8em;opacity:0.7" "live · refreshes every 3s in-app")
           (h2 "latency by route")
           (p :style "font-size:0.75em;opacity:0.7"
             (span :style "color:#4c9a8f" "▉ p50") "  "
@@ -505,9 +505,16 @@
           (unquote (otel/-traces-list traces)))))))
 
 ;; ── routes ────────────────────────────────────────────────────────────
+;; Dual-mode, wired into the SPA: a boosted (SX-Request) fetch — a link click OR
+;; the 3s poll — gets the dashboard as a text/sx fragment the WASM kernel renders
+;; into place; a direct/no-JS load gets the full SPA shell (host/blog--page) with
+;; the dashboard in #content, so it degrades to a plain server-rendered page.
+;; (Reuses the host SPA shell + content-type negotiation from lib/host/blog.sx.)
 (define otel/dashboard-route
   (dream-get "/otel"
-    (fn (req) (dream-html (render-to-html (otel/dashboard) {})))))
+    (fn (req)
+      (host/blog--resp req 200
+        (host/blog--page req "OpenTelemetry" (otel/dashboard))))))
 (define otel/stream-route
   (dream-get "/otel/stream"
     (fn (req)

lib/host/tests/otel.sx

@@ -234,7 +234,8 @@
 (host-ot-test "dashboard has the root id" (contains? host-ot-dash "otel-dashboard") true)
 (host-ot-test "dashboard SSRs the waterfall svg" (contains? host-ot-dash "<svg") true)
 (host-ot-test "dashboard shows a route in the strip" (contains? host-ot-dash "/feed") true)
-(host-ot-test "dashboard auto-refreshes (meta refresh, not fake SSE)" (contains? host-ot-dash "refresh") true)
+(host-ot-test "dashboard self-refreshes via SPA poll (sx-trigger)" (contains? host-ot-dash "every 3s") true)
+(host-ot-test "dashboard poll targets itself" (contains? host-ot-dash "otel-dashboard") true)
 (host-ot-test "dashboard shows the latency chart legend" (contains? host-ot-dash "p99 (tail)") true)
 
 ;; the SSE endpoint emits a span event, SSE-framed
@@ -252,13 +253,18 @@
 (define host-ot-ev (otel/latest-span-event))
 (host-ot-test "latest span event type" (str (get host-ot-ev :type)) "otel.span")
 
-;; mounted through make-app: GET /otel serves the dashboard page
+;; mounted through make-app: a BOOSTED GET /otel returns the text/sx fragment (the
+;; SPA path — serialize, no render-page, so it's conformance-safe). The direct/
+;; full-page path uses render-page (a server-env prim absent here) and is exercised
+;; live, not in conformance.
 (otel/reset!)
 (feed/reset!)
 (define host-ot-mapp (host/make-app (list host/feed-routes otel/routes)))
-(define host-ot-otelresp (host-ot-mapp (dream-request "GET" "/otel" {} "")))
-(host-ot-test "GET /otel status 200" (dream-status host-ot-otelresp) 200)
-(host-ot-test "GET /otel serves the dashboard"
+(define host-ot-otelresp (host-ot-mapp (dream-request "GET" "/otel" {"sx-request" "true"} "")))
+(host-ot-test "GET /otel (boosted) status 200" (dream-status host-ot-otelresp) 200)
+(host-ot-test "GET /otel (boosted) is text/sx"
+  (contains? (str (dream-headers host-ot-otelresp)) "text/sx") true)
+(host-ot-test "GET /otel (boosted) serves the dashboard fragment"
   (contains? (dream-resp-body host-ot-otelresp) "otel-dashboard") true)
 
 ;; empty ring → dashboard still SSRs (a placeholder, no svg)