Version extraction in FilenameExposer truncates multi-digit version numbers

In `FilenameExposer.java:35-40`, the regex only matches a single digit:

```java
private static final Pattern VERSION_PATTERN = Pattern.compile("-\\\\d"); // only matches single digit!
// ...
identification.addVersion(filename.substring(mat.end() - 1));
```

For a file like `my-lib-12.3.4.jar`:
- `mat.find()` matches `-1` at position 6-8
- `mat.end() - 1` = 7 ⇒ `filename.substring(7)` = `2.3.4`

The expected result is `12.3.4`. The pattern `-\\\\d` only matches `-` followed by a **single** digit, so any version starting with a multi-digit number (e.g., `10`, `12`, `21`) gets its first digit lopped off. This produces incorrect artifact identification for versions >= 10.

Start in FilenameExposer.java:35-40 and reproduce the issue with my-lib-12.3.4.jar. Trace how the regex match and substring determine the extracted version, then verify that multi-digit versions retain the complete value and that existing tests still pass.

Written by the indexing model from the issue text.