Is this a reproducible bug?

• I confirm this is a reproducible bug, not a feature request, idea, question, contribution proposal, or direction check.

Current behavior

After herdr server live-handoff --import-exe /usr/bin/herdr, herdr plugin list reports no plugins even though ~/.config/herdr/plugins.json existed with installed plugins. Running herdr plugin install ... afterward installs into the empty live registry and rewrites plugins.json with only that plugin.

Expected behavior

live handoff preserves plugins

Reproduction

1. Have one or more installed plugins in ~/.config/herdr/plugins.json.
2. Run herdr plugin list and confirm plugins are listed.
3. Run herdr server live-handoff --import-exe /usr/bin/herdr.
4. Run herdr plugin list.
5. Observe No plugins installed.
6. Run any herdr plugin install ....
7. Observe plugins.json is rewritten from the empty in-memory registry plus the newly installed plugin.

Impact

Live handoff requires reinstalling plugins

Environment

• Herdr version: 0.7.1
• Update channel (stable or preview): stable
• Operating system: Arch Linux, kernel 7.0.12-arch1-1
• Terminal: Ghostty (TERM_PROGRAM=ghostty, TERM=xterm-256color)
• Shell, if relevant: bash (/usr/bin/bash)
• Relevant config, if any: