Conflicting plugins detected

When two plugins register the same route, command ID, or decorator key and the host silently accepts both, behavior depends on which plugin loaded last — an implementation detail that changes across restarts, deploys, and config edits. ISO 25010 maintainability.modularity requires that namespace boundaries be enforced; silent last-wins collision is a namespace boundary failure. Operators cannot predict or debug behavior that changes based on plugin load order with no logged conflict.

Reject duplicate plugin names at load time with an explicit PluginConflictError. Extend conflict detection to namespace collisions (duplicate routes, commands, or decorator keys) as the plugin ecosystem grows.

function loadPlugin(manifest: PluginManifest) {
  if (this.plugins.has(manifest.name)) {
    throw new PluginConflictError(
      `Plugin "${manifest.name}" is already loaded. Cannot load a second plugin with the same name.`
    );
  }
  for (const conflict of manifest.conflicts ?? []) {
    if (this.plugins.has(conflict)) {
      throw new PluginConflictError(
        `Plugin "${manifest.name}" conflicts with loaded plugin "${conflict}".`
      );
    }
  }
}