uv tool update removes DataDesigner plugin installs

Summary

Running uv tool update data-designer at the tool level removes previously installed DataDesigner plugin packages from the tool environment. After each DataDesigner upgrade, users have to re-run individual plugin install commands to restore the plugins.

Reproduction

1. Install data-designer as a uv tool.
2. Install a DataDesigner plugin into the same tool environment, for example data-designer-github==0.1.0.
3. Run:

uv tool update data-designer

Observed command output from a real update:

Modified data-designer environment
- data-designer-github==0.1.0
- json-repair==0.59.9
+ json-repair==0.59.10
- ruff==0.15.12
+ ruff==0.15.13

Expected behavior

Updating the data-designer uv tool should preserve installed DataDesigner plugins in the tool environment, or provide an upgrade path that reinstalls registered plugins automatically.

Actual behavior

The update removes plugin packages such as data-designer-github, leaving the tool without previously installed plugin functionality.

Impact

Every data-designer tool upgrade requires users to remember which plugins were installed and manually re-run the individual tool/plugin install commands. This makes plugin use fragile and easy to break during routine upgrades.

Start by reproducing the issue with the listed uv tool installation, plugin installation, and update commands, then trace how DataDesigner plugins are registered and handled during tool updates. Done means an update preserves the installed data-designer-github plugin or provides an automatic reinstall path, with coverage for the reproduced scenario.