[Abstract] Overhaul `isVisible` in `App.jsx`

[Mikey-222]

Labels: frontend, advanced
Priority: P1

Description

A critical architectural review identified that isVisible suffers from insecure local storage access. This flaw exposes the system to degraded user experience on low-end devices. The engineering requirement is to abstract the function/variable to meet production standards.

Acceptance Criteria

• The insecure local storage access associated with isVisible is resolved.
• Edge cases leading to degraded user experience on low-end devices are handled.
• No regression in src/App.jsx execution.

Technical Context

Target: isVisible
File: src/App.jsx (Line ~106)

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