refactor: migrate CRM data layer from manual gqlFetch to Apollo Client

Replace custom gqlFetch() with proper Apollo useQuery/useMutation hooks
powered by codegen-generated TypedDocumentNode types. Key changes:

- Add GraphQL SDL schema file and codegen config for typescript-vue-apollo
- Replace all 28 raw .graphql imports with generated typed documents
- Add 12 useQuery() hooks with cache-and-network fetch policy
- Add 17 useMutation() hooks with surgical refetchQueries per mutation
- Optimistic cache update for setContactInboxHidden (instant archive UX)
- Fix contact list subtitle: show lastText instead of channel name
- Migrate login page from gqlFetch to useMutation
- WebSocket realtime now calls Apollo refetch instead of full data reload

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/app/pages/login.vue

@@ -1,39 +1,20 @@
 <script setup lang="ts">
 import CrmAuthLoginForm from "~~/app/components/workspace/auth/CrmAuthLoginForm.vue";
-import loginMutation from "~~/graphql/operations/login.graphql?raw";
+import { useMutation } from "@vue/apollo-composable";
+import { LoginMutationDocument } from "~~/graphql/generated";
 
 const phone = ref("");
 const password = ref("");
 const error = ref<string | null>(null);
 const busy = ref(false);
 
-async function gqlFetch<TData>(query: string, variables?: Record<string, unknown>) {
-  const headers = process.server ? useRequestHeaders(["cookie"]) : undefined;
-  const result = await $fetch<{ data?: TData; errors?: Array<{ message: string }> }>("/api/graphql", {
-    method: "POST",
-    headers,
-    body: { query, variables },
-  });
-
-  if (result.errors?.length) {
-    throw new Error(result.errors[0]?.message || "GraphQL request failed");
-  }
-
-  if (!result.data) {
-    throw new Error("GraphQL returned empty payload");
-  }
-
-  return result.data;
-}
+const { mutate: doLogin } = useMutation(LoginMutationDocument);
 
 async function submit() {
   error.value = null;
   busy.value = true;
   try {
-    await gqlFetch<{ login: { ok: boolean } }>(loginMutation, {
-      phone: phone.value,
-      password: password.value,
-    });
+    await doLogin({ phone: phone.value, password: password.value });
     await navigateTo("/", { replace: true });
   } catch (e: any) {
     error.value = e?.data?.message || e?.message || "Login failed";