LSP plugin installation ignores CLAUDE_CONFIG_DIR, uses hardcoded ~/.claude/

Description

When CLAUDE_CONFIG_DIR is set to a custom path, the LSP plugin installer resolves source paths relative to the hardcoded default ~/.claude/ instead of $CLAUDE_CONFIG_DIR. Installation fails even though the plugin files exist at the correct location under the custom config dir.

Steps to Reproduce

1. Set CLAUDE_CONFIG_DIR to a non-default path (e.g. /home/user/dotfiles/.claude)
2. Open a .rs file — Claude Code prompts to install rust-analyzer-lsp
3. Select "Yes, install rust-analyzer-lsp"

Error

Failed to install: Source path does not exist:
/home/anders/.claude/plugins/marketplaces/claude-plugins-official/plugins/rust-analyzer-lsp

Expected Behavior

The installer should resolve plugin source paths using $CLAUDE_CONFIG_DIR (or whatever resolved config dir is active), not the hardcoded ~/.claude/.

The plugin files are present at the correct location:
$CLAUDE_CONFIG_DIR/plugins/marketplaces/claude-plugins-official/plugins/rust-analyzer-lsp

Environment

• Claude Code: 2.1.138
• OS: Linux (Arch Linux 6.19.14)
• Shell: fish
• CLAUDE_CONFIG_DIR: set to a custom dotfiles path