Harden API client against stale-backend HTML fallback

When the running backend is missing a route, the SPA fallback serves index.html
with a 200, and the api helper returned undefined — which crashed pages on
.map/.length (the Delivery pipeline white-screened against an old build). Now a
non-JSON 2xx on an /api call throws a clear 'API is running an older build'
error instead, and PipelinePage defensively coerces its lists to arrays.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/lib/api.ts

@@ -21,7 +21,18 @@ async function request<T>(method: string, url: string, body?: unknown): Promise<
   }
 
   const contentType = response.headers.get('content-type') ?? ''
-  return contentType.includes('application/json') ? ((await response.json()) as T) : (undefined as T)
+  if (contentType.includes('application/json')) {
+    return (await response.json()) as T
+  }
+
+  // A non-JSON 2xx on an /api call is almost always the SPA fallback (index.html) — i.e. the route
+  // doesn't exist on the backend that's running (a stale build). Fail loudly so callers surface it,
+  // instead of returning undefined and letting the page crash on `.map`/`.length`.
+  if (url.startsWith('/api') && contentType.includes('text/html')) {
+    throw new Error(`Unexpected HTML from ${url}. The API is likely running an older build — restart the server.`)
+  }
+
+  return undefined as T
 }
 
 export const api = {

client/src/pages/PipelinePage.tsx

@@ -97,8 +97,8 @@ export function PipelinePage() {
         api.get<ChangeSummary[]>(`/api/orgboard/change-requests?organizationId=${organizationId}`),
         api.get<Division[]>(`/api/orgboard/divisions?organizationId=${organizationId}`).catch(() => []),
       ])
-      setRequests(list)
+      setRequests(Array.isArray(list) ? list : [])
-      setDivisions(divs)
+      setDivisions(Array.isArray(divs) ? divs : [])
     } catch (err) {
       toast.error((err as Error).message)
     }