[BUG] Learning output style plugin lose execute permission on reload

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?

Summary

Specifically, plugin hooks with type: "command" lose execute permission on reload

The learning-output-style plugin's SessionStart hook fails with a "SessionStart:resume hook error" because /reload-plugins (and presumably plugin updates) re-downloads plugin files from git without preserving the execute bit on shell scripts referenced by type: "command" hooks.

Root Cause

The plugin's hooks.json references a shell script handler:

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "${CLAUDE_PLUGIN_ROOT}/hooks-handlers/session-start.sh"
          }
        ]
      }
    ]
  }
}

When the plugin manager syncs/updates the plugin cache from the git repository, the session-start.sh file is written with 644 permissions (rw-rw-r--) instead of 755 (rwxrwxr-x). Since the hook uses type: "command", the shell tries to execute the script directly, which fails without the execute bit.

The explanatory-output-style plugin (which has an identical hook structure) does not have this issue because its cached version (2cd88e7947b7) retained the execute bit — likely because it was installed at an earlier time when the plugin manager handled permissions differently, or because its version was pinned and not re-downloaded.

Additional Observations

• The script itself is valid — running it manually with bash session-start.sh produces correct JSON output and exits 0
• chmod +x on the script fixes it temporarily, but /reload-plugins re-downloads the file and resets permissions to 644
• The plugin's plugin.json is also missing a version field, causing the install path to use unknown/ as the version directory — cosmetic but potentially related to the update/re-download behavior
• Multiple version-hash directories accumulate in the cache (e.g., b10b583de281, 79caa0d824ac, etc.) alongside unknown/, but installed_plugins.json always references unknown

Workaround

Move the hook content into ~/.claude/settings.json as a user-level hook using cat (which reads the file without needing execute permission):

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "cat ~/.claude/hooks/learning-output-style.json"
          }
        ]
      }
    ]
  }
}

Then disable the plugin in settings.json:

{
  "enabledPlugins": {
    "learning-output-style@claude-plugins-official": false
  }
}

Environment

• Claude Code CLI on Linux (Ubuntu, kernel 6.5.0-41-generic)
• Plugin source: claude-plugins-official marketplace
• Plugin: learning-output-style (no version field in plugin.json)

What Should Happen?

The plugin manager should either:

1. Preserve the execute bit from the git repository when writing files to the plugin cache, or
2. Automatically set the execute bit on files referenced by type: "command" hooks, or
3. Use bash <script> instead of direct execution for shell script hooks

Error Messages/Logs

"SessionStart:resume hook error" appears on starting claude-code session

Steps to Reproduce

1. Install the learning-output-style plugin (user scope)
2. Verify the plugin works on first install
3. Run /reload-plugins or wait for an automatic plugin update
4. Start a new session or resume an existing one
5. Observe "SessionStart:resume hook error"

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.82

Claude Code Version

2.1.84

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

• Claude Code CLI on Linux (Ubuntu, kernel 6.5.0-41-generic)
• Plugin source: claude-plugins-official marketplace
• Plugin: learning-output-style (no version field in plugin.json)