CVE description usually (always?) shows error message

**What happened**:

The "CVE Description" box in the TUI from `yardstick label explore` always shows `could not connect to grype db:`.

**What you expected to happen**:

To see a description if one is available.

**How to reproduce it (as minimally and precisely as possible)**:

In another repo where yardstick is used for label management and quality gate, run `yardstick label explore `. For example, in `vunnel`, run `cd tests/quality` then `uv run yardstick result list` then copy a UUID, then run `yardstick label explore `.

**Anything else we need to know?**:

**Environment**:
- Output of `yardstick version`:
- OS (e.g: `cat /etc/os-release` or similar):

Reproduce the failure with `yardstick label explore ` using the `vunnel` steps in the issue, and inspect the command's CVE Description path. Trace why it displays `could not connect to grype db:` and verify that an available CVE description is shown instead, while genuine connection failures remain understandable.

Written by the indexing model from the issue text.