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.

internal/pkg/dto/request/setup_readiness_req.go

@@ -1,3 +1,4 @@
+// Modified in AgentDeskFixes: safe, reviewed setup repairs and honest routing diagnostics.
 package request
 
 type SetupSimulateRouteRequest struct {
@@ -6,6 +7,8 @@ type SetupSimulateRouteRequest struct {
 }
 
 type SetupQuickFixRequest struct {
-	Action   string `json:"action" form:"action"`
-	EntityID int64  `json:"entity_id" form:"entity_id"`
+	Action       string `json:"action" form:"action"`
+	EntityID     int64  `json:"entity_id" form:"entity_id"`
+	Apply        bool   `json:"apply" form:"apply"`
+	PreviewToken string `json:"preview_token" form:"preview_token"`
 }