Plugin load-time errors. A plugin that did not load (an unmet dependency, a --plugin-dir entry that failed) is absent from plugins[]; a plugin that loaded without one of its components keeps its row and gets an entry here too. plugin is name@marketplace, or the positional inline[N] / synced[N] tag for a directory entry that failed before it had a name; type is a category from an open set (path-not-found, generic-error, manifest-validation-error, dependency-unsatisfied, hook-load-failed, …) — treat a value you do not recognize as a generic failure; message is display text. The key is omitted when there are no errors; CI can fail on (plugin_errors?.length ?? 0) > 0. A session whose frames are persisted server-side (a Remote Control worker) always omits this key — plugin diagnostics stay in the local log there, so an omitted key does not assert a clean load.