Disabled plugins still execute SessionStart hooks

Bug Description

When a plugin is set to enabledPlugins: false in ~/.claude/settings.json, its hooks still execute on every session start (startup, resume, clear, compact).

Steps to Reproduce

1. Install the Vercel plugin (official plugin from claude-plugins-official)
2. Disable it in ~/.claude/settings.json:

``json
"enabledPlugins": {
"vercel@claude-plugins-official": false
}
``

1. Open a new session or run /clear
2. Observe that the Vercel plugin's SessionStart hooks still fire:

• session-start-seen-skills.mjs
• session-start-profiler.mjs
• inject-claude-md.mjs

Expected Behavior

When enabledPlugins is set to false for a plugin, all plugin functionality should be disabled, including hooks, skills, commands, and agents.

Actual Behavior

Skills and commands appear to be disabled, but hooks defined in hooks/hooks.json within the plugin cache continue to execute. This means:

• The disabled plugin still injects system-reminder context into conversations
• The disabled plugin still runs profiler scripts and telemetry (trackDauActiveToday)
• The disabled plugin can override or interfere with other plugins' hooks

Impact

• Unwanted context injection pollutes the conversation (e.g., Vercel "greenfield" guidance in non-Vercel projects)
• Users who disable a plugin expect it to be fully inactive
• Interferes with other SessionStart hooks (e.g., custom hooks that load project-specific plugins)

Environment

• Platform: Windows 10 Pro
• Claude Code: latest
• Plugin: vercel@claude-plugins-official v0.40.0