TL;DR: your kats version imports a private scipy helper (_centered) that newer scipy removed. Upgrade kats to a release that no longer uses it, or pin scipy to an older version as a workaround.

## The error
```text
ImportError: cannot import name '_centered' from 'scipy.signal.signaltools'
```

## Fix it
1. Upgrade kats:
   ```
   pip install -U kats
   ```
   Expected: installs a kats release fixed for modern scipy.
2. Verify:
   ```
   python -c "import kats; print(kats.__version__)"
   ```
   Expected: imports cleanly.
3. Workaround if you cannot upgrade kats: pin scipy to a version that still ships the private helper:
   ```
   pip install "scipy<1.11"
   ```
   Expected: the old import path works again.

## When this applies
Use this when `import kats` raises this error and scipy is recent.

## When it does not apply
If your own code imports _centered, copy the tiny helper into your project instead of depending on scipy internals. If kats is already current, reinstall it.

## Compatibility
kats releases before the scipy-compat fix; scipy 1.11+ where the private helper is gone.

## Root cause
_centered was a private (underscore-prefixed) helper inside scipy.signal.signaltools, never public API. scipy removed it during cleanup, and kats imported it directly, so kats broke at import time on new scipy.

## Edge cases
Pinning old scipy can break other packages that need new scipy; upgrading kats is the durable fix. Private-name imports (leading underscore) are always at risk; treat any of them as a bug in the importing package.