Plugins belong to the project, and they load before it: the project file gained the field plugins: ["demo-plugin.js"] (default empty, no formatVersion bump), the Plugins tab's switch writes into it as an ordinary undo step (SetPluginActiveCommand) instead of into a server-wide plugins.json, and the start order is turned around - startPlugins only fetches the list of files, then editor.boot() runs and ProjectStore.load(id, prepare) hands the raw JSON through before it is deserialized, where pluginsOf(raw) reads the list and PluginManager.syncTo() activates exactly those; that is the point of the issue, because what a plugin registers has to stand there before normalizeGraph would throw it away as unknown (#126, #127), a project switch first stops what the new project does not name and then starts what it does, a file the server does not have is passed over silently, and after signing out the manager is dead so a late event cannot start anything in a torn-down session; on the server plugins.json, PluginStore::setActive, isActive, the route PUT ?r=plugins/{file} and the 403 for inactive modules are gone and GET ?r=plugins only answers {file,bytes,updatedAt}, which makes every plugin file fetchable - the consequence accepted in #117, written down in the wiki for #115 and #116; publishPlugins(root) only copies files now, the seeder switches the demo plugin on in the fixture project, and the Plugins tab carries a puzzle piece as its icon while only a plugin's own tab still goes without one (the knob and the socket are cubic curves, not arcs, which Pixi's parser draws as a spike after an L); 3 new e2e checks in module 38 and 5 new unit tests cover the project as the owner of the switch, its undo, the order, pluginsOf against crude input and an unknown file name (#119)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tools/seed-e2e.mjs

@@ -9,19 +9,19 @@
 import { fileURLToPath } from 'node:url';
 import { sineWav } from './lib/audio.mjs';
 import { edge, node, port, sceneObject, variable } from './lib/builders.mjs';
-import { publishPlugins } from './lib/plugins.mjs';
+import { DEMO_PLUGIN, publishPlugins } from './lib/plugins.mjs';
 import { PROJECTS, cliArgs, uploadFont, uploadSound, writeProject } from './lib/projects.mjs';
 import { adjustColorsShader } from './lib/shaders.mjs';
 
 const { projectId, baseUrl } = cliArgs('seed-e2e.mjs', PROJECTS.fixture);
 
 /**
- * The plugins that ship with the repository, where the editor loads them from and switched on –
- * the build does the same, this makes a run after a plain checkout independent of it, and puts the
- * demo plugin back on after a step (or a person) switched it off. The server is this checkout
- * (locally and in CI), so a file copy is enough.
+ * The plugins that ship with the repository, where the editor loads them from – the build does the
+ * same, this makes a run after a plain checkout independent of it. That the demo plugin is also
+ * switched on is part of the fixture project below (#119). The server is this checkout (locally
+ * and in CI), so a file copy is enough.
  */
-publishPlugins(fileURLToPath(new URL('..', import.meta.url)), { force: true });
+publishPlugins(fileURLToPath(new URL('..', import.meta.url)));
 
 /**
  * Two typefaces for the font step to pick and to drop. They are put on the server but not made
@@ -84,6 +84,9 @@ const project = {
   id: projectId,
   name: 'E2E fixture',
   activeSceneId: 'scene1',
+  // The demo plugin is switched on by the project since #119, not by a state file on the server –
+  // this is what step 38 finds running.
+  plugins: [DEMO_PLUGIN],
   assets: [
     {
       id: 'scene1',