Make the setup flow pass its own journeys and axe sweep

Run against the standalone build, the four journeys and the axe sweep
surfaced five things the unit tier could not see. The completion route
derives only once every question is settled, and Q6 stays pending for
somebody with no unit-bearing area — the confirm screen now passes the
questions the flow never showed before it completes. The dashboard seed
matched a JSON null where the unset column is a SQL NULL, so it never
landed; the retired step route carried the same filter. The auth shell's
onboarding branch matched only the front door, so every question screen
rendered inside the full app chrome with the sidebar. Inline links
relied on colour alone, the step list sat outside any landmark, and the
baseline form brought a second h1 onto the confirm screen. The two
sweeps run serially, since each drives one account through the API.

The integration file gains the seed case that would have caught the
null filter.

src/app/api/onboarding/complete/route.ts

@@ -242,12 +242,15 @@ async function completeNeedsFlow(
     // lands first — leaves `count = 0` and the seed is skipped rather than
     // overwriting it. An answer set that speaks to no tile builds `null` and
     // writes nothing, which leaves the default layout in place.
+    // `AnyNull`, not `JsonNull`: an unset column is a SQL NULL, which
+    // `JsonNull` (a JSON `null` value) does not match — the retired step route
+    // carried that filter and its seed never landed on a fresh account.
     const seededLayout = buildNeedsSeededDashboardLayout(state.needs);
     if (seededLayout) {
       const seeded = await prisma.user.updateMany({
         where: {
           id: userId,
-          dashboardWidgetsJson: { equals: Prisma.JsonNull },
+          dashboardWidgetsJson: { equals: Prisma.AnyNull },
         },
         data: { dashboardWidgetsJson: toJson(seededLayout) },
       });