Add correction for SPHEREx PSF zone info

[troyraen]

A bug has been discovered in the SPHEREx PSF zone information in the header. The zones are indexed the wrong way (x <-> y zone centers swapped). The data will be corrected, but in the meantime we should update the PSF notebook to warn the user and show how to correct it manually.

Also add something about this in the PSF section of the spherex_intro notebook.

[troyraen]

We should tell people what to do with both versions of the header data, in case they don't want to re-download. This came out of a spherex meeting. Some relevant notes are here: https://confluence.ipac.caltech.edu/spaces/IRSA/pages/785975583/PSF+header+update.

[afaisst]

Created new branch:
https://github.com/Caltech-IPAC/irsa-tutorials/blob/psf-fix-Faisst_mar102026/tutorials/spherex/spherex_psf.md

Started implementing changes.

• new learning goals
• link to erratum explaining changes in PSF header
• query version of images and decide if PSF header needs to be updated
• added function to update PSF header

To do:

• reading and updating version of image header to correct one (currently placeholder, e.g. 6.4 -> 6.4-001).
• add weblink to erratum explaining PSF header changes.

[afaisst]

Waiting for SPHEREx developer team to decide on version numbering of fixed images.