Fix: Keep snapshot, history, and note lists stable after deletion

[DevMando]

Problem

Deleting a snapshot, past conversation, or note rebuilt the entire list. The remaining cards and project groups were recreated, causing them to slide up again and making it harder to continue browsing or deleting items.

What changes

These panels now update existing lists instead of replacing them. A deletion removes the affected card while keeping surviving cards and expanded groups in place. Group counts and “Delete all” labels update immediately, and list entrance animations are disabled.

The same approach also avoids a second full redraw when Notes rescans the folder after a deletion. Search results, edited items, and ordering still update when their underlying data changes.

This follows the existing Skills/MCP approach of keeping rows stable. Skills and MCP are not changed by this PR.

Validation

• Desktop build passed with zero warnings and errors, using a separate output folder to avoid interfering with the running app.
• Three regression tests passed: deleting and rescanning preserves surviving rows; edits and ordering update without resetting the list; removing a group preserves the remaining group.
• A manual walkthrough of the WinUI animation and scrolling behavior is still needed.