feat: community and custom plugin registries

src/backend/sync/client/plugins.ts

@@ -21,6 +21,7 @@ import {
   unloadPlugin,
 } from "../../plugins/index.js";
 import { getPluginsDir } from "../../plugins/paths.js";
+import { setSyncedRegistryKeys } from "../../plugins/registries.js";
 import type { LoadedPlugin } from "../../plugins/loader.js";
 import {
   createCurrentPluginPermissionGrantRepository,
@@ -283,10 +284,12 @@ async function mirrorOne(link: SyncLink, plugin: RemotePlugin): Promise<void> {
 }
 
 export async function mirrorPlugins(link: SyncLink): Promise<void> {
-  const { plugins } = await remoteJson<{ plugins: RemotePlugin[] }>(
-    link,
-    "/sync/v2/plugins",
-  );
+  const { plugins, registryKeys } = await remoteJson<{
+    plugins: RemotePlugin[];
+    registryKeys?: unknown[];
+  }>(link, "/sync/v2/plugins");
+  // Before any download: a plugin from a custom registry needs its key.
+  await setSyncedRegistryKeys(Array.isArray(registryKeys) ? registryKeys : []);
   lastRemote = plugins;
   const remoteIds = new Set(plugins.map((plugin) => plugin.id));
 

src/backend/sync/server/routes.ts

@@ -472,7 +472,7 @@ async function listPluginsForDesktop() {
  * /sync/v2/plugins:
  *   get:
  *     summary: The features this server runs, for a linked desktop to mirror
- *     description: Every installed plugin with its version, where it came from, whether it is on, how a desktop should treat it and which sync entities it owns.
+ *     description: Every installed plugin with its version, where it came from, whether it is on, how a desktop should treat it and which sync entities it owns. registryKeys lists the signing keys of the custom registries an admin added, so plugins from them load on the desktop.
  *     tags:
  *       - Sync
  *     responses:
@@ -509,7 +509,9 @@ router.get(
           ),
         });
       }
-      res.json({ plugins });
+      const { customRegistryKeys } =
+        await import("../../plugins/registries.js");
+      res.json({ plugins, registryKeys: await customRegistryKeys() });
     } catch (error) {
       syncLogger.error("Failed to list plugins for sync", error, {
         operation: "sync_plugins",