fix(plugin-install): save installed plugins to config

The plugin-install command now saves installed plugins to the AIPM config
file (.aipm/config.json), making them available for sync and uninstall
operations.

This fixes the broken workflow where:
- Plugins installed with 'aipm plugin install' weren't tracked in config
- 'aipm sync' couldn't find them (reads from config.plugins)
- 'aipm uninstall' would fail (checks if plugin exists in config)

Also made AIPM config required for plugin-install (not optional) and added
a check to prevent re-installing already-installed plugins.

Author: yordis

src/commands/plugin-install.ts

@@ -4,6 +4,7 @@ import { z } from 'zod';
 import { loadClaudeCodeMarketplaces, loadPluginsConfig } from '../config/loader';
 import { DIR_CURSOR } from '../constants';
 import { getErrorMessage } from '../errors';
+import { loadTargetConfig, saveConfig } from '../helpers/aipm-config';
 import { isClaudeCodeInstalled } from '../helpers/claude-code-config';
 import { fileExists } from '../helpers/fs';
 import { resolveMarketplacePath } from '../helpers/git';
@@ -26,18 +27,14 @@ export async function pluginInstall(options: unknown): Promise<void> {
   try {
     const { pluginName, marketplaceName } = parsePluginId(cmd.pluginId);
 
-    // Load marketplaces from both AIPM config (optional) and Claude Code (auto-discovered)
-    let aipmMarketplaces: Record<string, any> = {};
-    try {
-      const config = await loadPluginsConfig(cwd);
-      aipmMarketplaces = config.config.marketplaces || {};
-    } catch (error: unknown) {
-      // AIPM config is optional - proceed without it
-      // Log at info level so users know about config issues but can continue
-      if (!(error instanceof Error && error.message.includes('not found'))) {
-        const message = getErrorMessage(error);
-        defaultIO.logInfo(`ℹ️  Config loading: ${message}`);
-      }
+    // Load AIPM config - required for plugin-install to track installed plugins
+    let { config } = await loadPluginsConfig(cwd);
+    let aipmMarketplaces: Record<string, any> = config.marketplaces || {};
+
+    // Check if plugin is already installed
+    if (config.plugins[cmd.pluginId]) {
+      defaultIO.logInfo(`Plugin '${cmd.pluginId}' is already installed`);
+      return;
     }
 
     const claudeMarketplaces = await loadClaudeCodeMarketplaces();
@@ -150,9 +147,17 @@ export async function pluginInstall(options: unknown): Promise<void> {
       syncResult = await syncPluginToCursor(pluginPath, marketplaceName, pluginName, cursorDir);
     }
 
+    // Save plugin to AIPM config to make it available for sync and uninstall
+    const targetConfig = await loadTargetConfig(cwd, false);
+    const updatedConfig = merge({}, targetConfig, {
+      plugins: { [cmd.pluginId]: { enabled: true } },
+    });
+    await saveConfig(cwd, updatedConfig, false);
+
     const summary = formatSyncResult(syncResult);
 
     defaultIO.logSuccess(`Installed ${cmd.pluginId}`);
+    defaultIO.logSuccess(`Added plugin '${cmd.pluginId}' to .aipm/config.json`);
     console.log(`\n✨ Plugin '${cmd.pluginId}' installed successfully! (${summary})\n`);
   } catch (error: unknown) {
     const message = getErrorMessage(error);