auth: route tenant-less sign-in to onboarding instead of erroring out

Previously, signing in with a kind toggle when the account had no
tenant_settings row in the lab database returned 'Bu hesap için kayıt
bulunamadı'. For a freshly-imported isletmem user that has never opened
DLS, the right behaviour is onboarding — not a dead end.

resolveTenantOnLogin now distinguishes three states:
  - no_tenants  → redirect /onboarding?kind=<pill>  (session stays)
  - mismatch    → real error naming the existing kind, session rolled back
  - matched     → existing tenant set as active, /dashboard

Onboarding page accepts ?kind= and the workspace form pre-selects it, so
the user keeps their login pill choice without re-picking. Also fixed the
'teams.total > 0' redirect — it now requires a tenant_settings row before
sending users off to /dashboard, otherwise users with cross-app teams but
no DLS workspace would bounce.

src/app/onboarding/components/create-workspace-form.tsx

@@ -17,10 +17,15 @@ type Kind = "lab" | "clinic";
 interface Props {
   userName?: string;
   crossAppTeams?: Array<{ $id: string; name: string }>;
+  initialKind?: Kind | null;
 }
 
-export function CreateWorkspaceForm({ userName, crossAppTeams = [] }: Props) {
-  const [kind, setKind] = useState<Kind | null>(null);
+export function CreateWorkspaceForm({
+  userName,
+  crossAppTeams = [],
+  initialKind = null,
+}: Props) {
+  const [kind, setKind] = useState<Kind | null>(initialKind);
   const [state, formAction, isPending] = useActionState(
     createWorkspaceAction,
     initialWorkspaceState,

src/app/onboarding/page.tsx

@@ -1,7 +1,9 @@
 import type { Metadata } from "next";
 import { redirect } from "next/navigation";
+import { Query } from "node-appwrite";
 
-import { getCurrentUser } from "@/lib/appwrite/server";
+import { createAdminClient, getCurrentUser } from "@/lib/appwrite/server";
+import { DATABASE_ID, TABLES, type TenantKind } from "@/lib/appwrite/schema";
 import { getUserTeams, getCrossAppTeams } from "@/lib/appwrite/tenant";
 import { CreateWorkspaceForm } from "./components/create-workspace-form";
 
@@ -10,21 +12,43 @@ export const metadata: Metadata = {
   description: "DLS için ilk çalışma alanınızı kurun.",
 };
 
-export default async function OnboardingPage() {
+export default async function OnboardingPage({
+  searchParams,
+}: {
+  searchParams: Promise<{ kind?: string }>;
+}) {
   const user = await getCurrentUser();
   if (!user) redirect("/sign-in");
 
+  // Already has a DLS tenant? Send to dashboard. Cross-app teams without a
+  // tenant_settings row in `lab` still belong on onboarding.
   const teams = await getUserTeams();
-  if (teams && teams.total > 0) redirect("/dashboard");
+  if (teams && teams.total > 0) {
+    const { tablesDB } = createAdminClient();
+    const existing = await tablesDB.listRows({
+      databaseId: DATABASE_ID,
+      tableId: TABLES.tenantSettings,
+      queries: [
+        Query.equal("tenantId", teams.teams.map((t) => t.$id)),
+        Query.limit(1),
+      ],
+    });
+    if (existing.total > 0) redirect("/dashboard");
+  }
 
   const crossAppTeams = await getCrossAppTeams();
 
+  const { kind: rawKind } = await searchParams;
+  const initialKind: TenantKind | null =
+    rawKind === "lab" || rawKind === "clinic" ? rawKind : null;
+
   return (
     <div className="bg-muted flex min-h-svh flex-col items-center justify-center p-6 md:p-10">
       <div className="w-full max-w-md">
         <CreateWorkspaceForm
           userName={user.name?.split(" ")[0]}
           crossAppTeams={crossAppTeams}
+          initialKind={initialKind}
         />
       </div>
     </div>