Add support for runtime error status in plugins

Distinguish a loaded plugin whose
capability errored (RuntimeError,
warn-styled, stays checked) from a
load-time Error. Status now derives
via resolve_plugin_status(); enum
ordinal keeps dialog sort priority.
Unloading clears stale errors.

resources/web/dialog/PluginsDialog/index.js

@@ -1347,6 +1347,8 @@ function StatusDescription(plugin) {
       return "This plugin is still loading.";
     case "Error":
       return "This plugin is blocked until its error is fixed.";
+    case "RuntimeError":
+      return "This plugin is loaded but a capability reported an error.";
     case "Inactive":
     default:
       return "This plugin is inactive. Activate it to install or load it.";