DO NOT MERGE Add item description creator workflow

[RANGROO]

What

• Adds a Description Creator tab to the Description Manager for captured Prisma item images.
• Adds server-side CSV generation, saved CSV browsing, inline CSV description editing, import, delete, download, and CHIM mod zip packaging.
• Adds image thumbnails to the regular Description Manager table when an item image matches plugin + baseid.
• Tightens the item image description prompt and prompt migrations to avoid item-name leakage and image-framing phrasing.

Screenshot

Not included.

Why

Generate reviewable Description Manager CSVs from captured in-game item images, while keeping generated descriptions tied to stable plugin + baseid item keys.

Maintainer Discussion

• I discussed this PR with RANGROO or tyler.maister in Discord.

Related PRs

Companion CHIM PR: https://github.com/Dwemer-Dynamics/CHIM/pull/42

Notes

• Depends on the CHIM branch that captures Prisma item model previews and uploads item image metadata.
• Runtime DB prompt migration target is prompts version 20260614005.
• Validation run locally: php -l ui/api/description_creator.php, php -l ui/description_upload.php, php -l debug/db_updates.php, php -l lib/runtime_bootstrap.php, full local deploy completed successfully in prior validation.