feat(portal): C3BOX async progressive rendering with public ACL

- Async progressive cache: instant render from localStorage, async RPC updates
- Public ACL: unauthenticated access for secubox-public/portal route
- Progressive DOM updates via updateText() helpers
- No blocking Promise.all - each fetch updates its section on completion

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package/secubox/luci-app-secubox-portal/root/usr/share/luci/menu.d/luci-app-secubox-portal.json

@@ -68,7 +68,16 @@
 		"title": "SecuBox",
 		"order": 99,
 		"action": {
-			"type": "firstchild"
+			"type": "alias",
+			"path": "secubox-public/portal"
+		}
+	},
+	"secubox-public/portal": {
+		"title": "C3BOX Portal",
+		"order": 1,
+		"action": {
+			"type": "view",
+			"path": "secubox-portal/index"
 		}
 	},
 	"secubox-public/bugbounty": {

package/secubox/luci-app-secubox-portal/root/usr/share/rpcd/acl.d/luci-app-secubox-portal.json

@@ -23,9 +23,34 @@
 					"get_health",
 					"get_components",
 					"list_services"
-				]
+				],
+				"system": ["board", "info"]
 			}
 		},
 		"write": {}
+	},
+	"unauthenticated": {
+		"description": "Public access for SecuBox Portal",
+		"read": {
+			"ubus": {
+				"luci.secubox": [
+					"modules",
+					"getModules",
+					"modules_by_category",
+					"get_theme",
+					"getStatus",
+					"getHealth",
+					"get_services"
+				],
+				"luci.system-hub": [
+					"status",
+					"get_system_info",
+					"get_health",
+					"get_components",
+					"list_services"
+				],
+				"system": ["board", "info"]
+			}
+		}
 	}
 }