Fix/collection-gallery

[j-audrick]

PR Summary: Fix Collection Slot Updates Not Persisting and Rendering

This PR fixes an issue where users could run qsetcollection successfully but see no visible update in qshowcollection.

Root Cause

The in-memory user cache merge logic did not correctly handle dotted update paths containing list indices (example: collections.iu.0).

When qsetcollection updated a slot, the cached collection structure could be reshaped incorrectly (list-like data treated as dict-like), so later reads and rendering in qshowcollection appeared unchanged.

What Changed

1. Fixed dotted-path in-memory merge to support list indices safely

• Updated traversal and write behavior in update_user.
• Added index-aware handling for set, unset, inc, and pathing behavior for push and pull flows.

2. Added collection shape normalization on user load

• Added a normalization helper to repair corrupted collection shapes in cache (numeric-key dicts converted back into 6-slot lists).
• This makes the fix resilient for users already affected before deployment.

3. Fixed collection modal edge case

• Initialized card before conditional lookup to avoid undefined-variable behavior when clearing a slot.
• Stored and reused resolved card id consistently for local view state and logs.

This branch has commits from chii/fixes. Probably better to merge that first