feat: add plugin update tracking

src/plugins/installs.ts

@@ -0,0 +1,27 @@
+import type { ClawdbotConfig } from "../config/config.js";
+import type { PluginInstallRecord } from "../config/types.plugins.js";
+
+export type PluginInstallUpdate = PluginInstallRecord & { pluginId: string };
+
+export function recordPluginInstall(cfg: ClawdbotConfig, update: PluginInstallUpdate): ClawdbotConfig {
+  const { pluginId, ...record } = update;
+  const installs = {
+    ...cfg.plugins?.installs,
+    [pluginId]: {
+      ...cfg.plugins?.installs?.[pluginId],
+      ...record,
+      installedAt: record.installedAt ?? new Date().toISOString(),
+    },
+  };
+
+  return {
+    ...cfg,
+    plugins: {
+      ...cfg.plugins,
+      installs: {
+        ...installs,
+        [pluginId]: installs[pluginId],
+      },
+    },
+  };
+}