[Bug] Plugin install command reports success but fails to persist plugin data

Bug Description
Title: Plugin install reports success but doesn't actually install plugins (v2.0.59)

Environment:

• Claude Code version: 2.0.59
• Installation method: Homebrew
• OS: Linux 6.8.0-101-generic

Description:
The claude plugin install command reports "Successfully installed" but plugins are never actually installed. The installed_plugins.json file is not created/updated and the cache directory
remains empty.

Steps to Reproduce:

1. Clear all plugin data:

rm -rf ~/.claude/plugins/cache/*
rm -f ~/.claude/plugins/installed_plugins.json
rm -rf ~/.claude/plugins/marketplaces/*
rm -f ~/.claude/plugins/known_marketplaces.json

1. Add marketplace:

claude plugin marketplace add anthropics/claude-plugins-official
# Output: ✔ Successfully added marketplace: claude-plugins-official

1. Install a plugin:

claude plugin install pr-review-toolkit@claude-plugins-official
# Output: ✔ Successfully installed plugin: pr-review-toolkit@claude-plugins-official

1. Check installation:

cat ~/.claude/plugins/installed_plugins.json
# Result: File doesn't exist
ls ~/.claude/plugins/cache/
# Result: Empty directory

Debug log evidence:
Found 0 plugins (0 enabled, 0 disabled)
0 marketplaces, 0 installable plugins, 0 uninstallable plugins
Loaded plugins - Enabled: 0, Disabled: 0, Commands: 0, Agents: 0, Errors: 0

Expected behavior:

• installed_plugins.json should be created/updated with the plugin entry
• Plugin files should be cached in ~/.claude/plugins/cache/
• /plugin command should show installed plugins

Actual behavior:

• Install command returns success
• No files are written
• /plugin command returns nothing
• Debug log shows 0 plugins loaded

Environment Info

• Platform: linux
• Terminal: gnome-terminal
• Version: 2.0.59
• Feedback ID: fef5c990-6643-48a1-be73-8efcd11cf5dd

Errors

[{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:27:09.249Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:28:20.541Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:28:35.577Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:29:19.545Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:29:35.390Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:29:50.738Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:862:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/claude:176:2147)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-03-07T21:30:07.898Z"},{"error":"Error\n    at PS (/$bunfs/root/claude:173:1143)\n    at <anonymous> (/$bunfs/root/claude:174:10086)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/re

Note: Error logs were truncated.