fix: sidebar messing with tile size

[JammingBen]

fixes #1359

[Copilot]

Pull Request Overview

Fix sidebar affecting tile size by reacting to sidebar open state and preventing invalid CSS variable updates.

• Add a guard to avoid setting the tile size CSS variable when the value is invalid.
• Trigger tile width recalculation when the sidebar opens/closes.
• Add a FIXME in useSideBar noting the need for a global store to avoid duplicate listeners.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
packages/web-pkg/src/composables/sideBar/useSideBar.ts	Adds a FIXME comment referencing migrating to a global store to prevent multiple event listeners.
packages/web-pkg/src/components/FilesList/ResourceTiles.vue	Imports useSideBar, watches sidebar open state to recalc view width, and guards setting the CSS variable only when tile size is valid.

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