fix(docs): Guard localStorage access in restricted environments

[sentry]

DESCRIBE YOUR PR

This PR addresses issue DOCS-A43, "TypeError: null is not an object (evaluating 'localStorage.setItem')", which occurred in browsers with restricted storage access like Safari Private Browsing and Android WebViews.

The root cause was unconditional access to localStorage in several components, which can be null or throw a SecurityError upon access in these environments.

Changes Made:

1. Strengthened isLocalStorageAvailable utility (src/utils.ts): The utility now uses a try/catch block to robustly check for localStorage availability, correctly handling cases where window.localStorage is null or throws a SecurityError.
2. Applied isLocalStorageAvailable guard: All localStorage.setItem, localStorage.getItem, and localStorage.removeItem calls in the following components are now wrapped with the isLocalStorageAvailable check:
   • src/components/platformSelector/index.tsx
   • src/components/TopNavClient.tsx
   • src/components/sidebar/MobileSidebarNav.tsx
   • src/components/breadcrumbs/index.tsx

This ensures that localStorage operations only occur when storage is genuinely available and accessible, preventing crashes and allowing for graceful degradation in restricted contexts.

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PRE-MERGE CHECKLIST

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• Checked Vercel preview for correctness, including links
• PR was reviewed and approved by any necessary SMEs (subject matter experts)
• PR was reviewed and approved by a member of the Sentry docs team

LEGAL BOILERPLATE

Look, I get it. The entity doing business as "Sentry" was incorporated in the State of Delaware in 2015 as Functional Software, Inc. and is gonna need some rights from me in order to utilize my contributions in this here PR. So here's the deal: I retain all rights, title and interest in and to my contributions, and by keeping this boilerplate intact I confirm that Sentry can use, modify, copy, and redistribute my contributions, under Sentry's choice of terms.

EXTRA RESOURCES

• Sentry Docs contributor guide

Fixes DOCS-A43

_{Comment @sentry <feedback> on this PR to have Autofix iterate on the changes.}

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Project	Deployment	Actions	Updated (UTC)
develop-docs	Ready	Preview	Aug 2, 2026 10:57am
sentry-docs	Ready	Preview	Aug 2, 2026 10:57am