fix: harden identity, live access, drafts and setup (review only)

Source-reviewed hardening changes and regression tests. UNBUILT / UNTESTED: not a deployable release. Go formatting, compilation, automated regression tests, full frontend validation and staging acceptance remain required. See docs/hardening/VALIDATION.md. Main remains the original clean snapshot; no upstream Git history imported.

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 {
@@ -8,4 +9,6 @@ type SetupSimulateRouteRequest struct {
 type SetupQuickFixRequest struct {
 	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"`
 }