[BUG] "X plugins failed to install" on first launch due to race condition with marketplace auto-install

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description

On first launch with enabledPlugins configured in .claude/settings.json, Claude Code shows "x plugins failed to install" even though the official marketplace auto-installs successfully moments later.

## Root Cause

The plugin loading check runs before the marketplace auto-install completes:

16:07:14.009Z [DEBUG] Attempting to auto-install official marketplace
16:07:14.017Z [DEBUG] Cannot install 6 plugins because their marketplaces are not installed
16:07:14.046Z [DEBUG] Adding notification for 6 failed installations ← triggered here
16:07:15.091Z [DEBUG] Successfully auto-installed official marketplace ← completes ~1s later

## Steps to Reproduce

1. Fresh environment (e.g., new devcontainer) with no ~/.claude directory
2. Configure .claude/settings.json with enabledPlugins:

```json
{
"enabledPlugins": {
"feature-dev@claude-plugins-official": true,
"code-review@claude-plugins-official": true
}
}

1. Launch Claude Code for the first time
2. See "X plugins failed to install" notification

Expected Behavior

Plugins should install automatically after the marketplace auto-install completes, or the notification should be deferred until after marketplace setup.

Actual Behavior

• Notification shows plugins "failed to install"
• Marketplace installs successfully in background
• Plugins remain uninstalled until manually installed via /plugin install

Workaround

Run claude plugin install <plugin>@claude-plugins-official manually after first launch.

Environment

• Claude Code: 2.1.12
• Platform: Linux (Docker/devcontainer)
• Installation: Native

Related Issues

• #15569 - Similar timing issue with marketplace notification
• #17089 - Plugin persistence issues after 2.1.x

What Should Happen?

Expected Behavior

Plugins should install automatically after the marketplace auto-install completes, or the notification should be deferred until after marketplace setup.

Error Messages/Logs

Steps to Reproduce

1. Fresh environment (e.g., new devcontainer) with no ~/.claude directory
2. Configure .claude/settings.json with enabledPlugins:

```json
{
"enabledPlugins": {
"feature-dev@claude-plugins-official": true,
"code-review@claude-plugins-official": true
}
}

1. Launch Claude Code for the first time
2. See "X plugins failed to install" notification

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.12

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_