feat: persist support ticket drafts

frontend/src/lib/components/patterns/webapp/TicketComposer.svelte

@@ -14,6 +14,12 @@
     if (disabled || sending || !value.trim()) return;
     onSend(value.trim());
   }
+
+  function handleKeydown(event) {
+    if (!(event.ctrlKey || event.metaKey) || event.key !== "Enter") return;
+    event.preventDefault();
+    submit();
+  }
 </script>
 
 <div class="ticket-composer">
@@ -25,6 +31,7 @@
     {placeholder}
     ariaLabel={placeholder}
     class="ticket-composer-textarea"
+    on:keydown={handleKeydown}
   />
   <div class="ticket-composer-row">
     <small>{value.length}/{maxLength}</small>

frontend/src/lib/webapp/stores/supportStore.js

@@ -250,7 +250,7 @@ export function createSupportStore({ api, t, showToast }) {
     });
     if (!ticketId) {
       state.update((s) => ({ ...s, sending: false }));
-      return;
+      return false;
     }
     try {
       const res = await api(`/support/tickets/${ticketId}/messages`, {
@@ -265,8 +265,10 @@ export function createSupportStore({ api, t, showToast }) {
       }));
       await refreshUnread();
       await loadList({ silent: true, force: true });
+      return true;
     } catch (error) {
       showToast(error?.message || t("wa_support_send_failed"));
+      return false;
     } finally {
       state.update((s) => ({ ...s, sending: false }));
     }

frontend/src/lib/webapp/supportDrafts.js

@@ -0,0 +1,83 @@
+const SUPPORT_DRAFT_STORAGE_PREFIX = "rw_webapp_support_draft_v1";
+const SUPPORT_DRAFT_TTL_MS = 14 * 24 * 60 * 60 * 1000;
+const DEFAULT_SCOPE = "anonymous";
+
+function safeStorage() {
+  if (typeof window === "undefined") return null;
+  try {
+    return window.localStorage || null;
+  } catch (_error) {
+    return null;
+  }
+}
+
+function draftKey(kind, scope, id = "new") {
+  return [
+    SUPPORT_DRAFT_STORAGE_PREFIX,
+    encodeURIComponent(String(kind || "draft")),
+    encodeURIComponent(String(scope || DEFAULT_SCOPE)),
+    encodeURIComponent(String(id || "new")),
+  ].join(":");
+}
+
+function normalizeDraftEnvelope(value) {
+  if (!value || typeof value !== "object") return null;
+  const updatedAt = Number(value.updatedAt || 0);
+  if (!updatedAt || Date.now() - updatedAt > SUPPORT_DRAFT_TTL_MS) return null;
+  return value.draft && typeof value.draft === "object" ? value.draft : null;
+}
+
+export function supportDraftScope(user = {}) {
+  const id = String(user?.user_id ?? user?.id ?? user?.telegram_id ?? "").trim();
+  return id || DEFAULT_SCOPE;
+}
+
+export function readSupportDraft(kind, scope, id = "new") {
+  const storage = safeStorage();
+  if (!storage) return null;
+  const key = draftKey(kind, scope, id);
+
+  try {
+    const raw = storage.getItem(key);
+    if (!raw) return null;
+
+    const draft = normalizeDraftEnvelope(JSON.parse(raw));
+    if (!draft) storage.removeItem(key);
+    return draft;
+  } catch (_error) {
+    try {
+      storage.removeItem(key);
+    } catch (_removeError) {
+      void _removeError;
+    }
+    return null;
+  }
+}
+
+export function writeSupportDraft(kind, scope, id = "new", draft = {}) {
+  const storage = safeStorage();
+  if (!storage) return;
+
+  try {
+    storage.setItem(
+      draftKey(kind, scope, id),
+      JSON.stringify({
+        updatedAt: Date.now(),
+        draft: draft && typeof draft === "object" ? draft : {},
+      })
+    );
+  } catch (_error) {
+    void _error;
+  }
+}
+
+export function clearSupportDraft(kind, scope, id = "new") {
+  const storage = safeStorage();
+  if (!storage) return;
+
+  try {
+    storage.removeItem(draftKey(kind, scope, id));
+  } catch (_error) {
+    void _error;
+  }
+}