feat: harden support, localize knowledge and add operator availability [skip ci]

Source-only publication of reviewed commit 64e96a7f423673dc29ad56485be9fc79bce8af1c.

Passed in isolation: focused frontend/backend tests, race checks, TypeScript typecheck, lint, Go compilation, Flowgram build, and deterministic SDK build/tests.

Not accepted as a production release: Next.js export/native assembly remains blocked by environment memory limits; browser interaction and MySQL staging acceptance remain unverified. No production server, database/schema, runtime configuration, deployment, release tag, or workflow execution was performed.

Expected source tree: 0a4a7528e9.

web/components/conversation-actions/transfer-dialog.tsx

@@ -1,3 +1,4 @@
+// Modified in this independent fork for support availability; see docs/hardening/README.md.
 "use client"
 
 import { zodResolver } from "@hookform/resolvers/zod"
@@ -26,9 +27,8 @@ import { Textarea } from "@/components/ui/textarea"
 import {
   assignConversation,
   transferConversation,
-  fetchAgentProfilesAll,
-  type AdminAgentProfile,
 } from "@/lib/api/admin"
+import { fetchAvailabilityAgents, type OperatorAvailability } from "@/lib/api/support-availability"
 import { useI18n } from "@/i18n/provider"
 
 type ConversationTransferDialogProps = {
@@ -87,10 +87,10 @@ function ConversationTransferDialogBody({
   const t = useI18n()
   const [saving, setSaving] = useState(false)
   const [loadingAgents, setLoadingAgents] = useState(false)
-  const [agents, setAgents] = useState<AdminAgentProfile[]>([])
+  const [agents, setAgents] = useState<OperatorAvailability[]>([])
   const userOptions = agents.map((agent) => ({
     value: String(agent.userId),
-    label: agent.displayName || agent.nickname || agent.username || t("conversationAction.agentFallback", { id: agent.userId }),
+    label: agent.displayName || t("conversationAction.agentFallback", { id: agent.userId }),
   }))
 
   const transferSchema = useMemo(
@@ -123,18 +123,25 @@ function ConversationTransferDialogBody({
   }, [conversationId, reset])
 
   useEffect(() => {
+    if (!conversationId) {
+      setAgents([])
+      setLoadingAgents(false)
+      return
+    }
     setLoadingAgents(true)
-    fetchAgentProfilesAll()
+    let active = true
+    fetchAvailabilityAgents(conversationId)
       .then((data) => {
-        setAgents(data.filter((item) => item.serviceStatus === 0))
+        if (active) setAgents(data.filter((item) => item.eligible))
       })
       .catch((error) => {
-        toast.error(error instanceof Error ? error.message : t("conversationAction.loadAgentsFailed"))
+        if (active) toast.error(error instanceof Error ? error.message : t("conversationAction.loadAgentsFailed"))
       })
       .finally(() => {
-        setLoadingAgents(false)
+        if (active) setLoadingAgents(false)
       })
-  }, [t])
+    return () => { active = false }
+  }, [t, conversationId])
 
   async function onFormSubmit(values: TransferForm) {
     if (!conversationId) {
@@ -194,13 +201,15 @@ function ConversationTransferDialogBody({
                     value={field.value}
                     options={userOptions}
                     placeholder={
-                      loadingAgents
+                      !conversationId
+                        ? t("conversationAction.conversationMissing")
+                        : loadingAgents
                         ? t("conversationAction.loading")
                         : t("conversationAction.selectTargetAgent")
                     }
                     searchPlaceholder={t("conversationAction.searchAgent")}
                     emptyText={t("conversationAction.emptyAgents")}
-                    disabled={saving || loadingAgents}
+                    disabled={saving || loadingAgents || !conversationId}
                     onChange={field.onChange}
                   />
                 )}
@@ -237,7 +246,7 @@ function ConversationTransferDialogBody({
           >
             {t("conversationAction.cancel")}
           </Button>
-          <Button type="submit" disabled={saving}>
+          <Button type="submit" disabled={saving || loadingAgents || !conversationId || agents.length === 0}>
             <ArrowRightLeftIcon />
             {saving
               ? isAssign