Error handling improvements

[mykhailodanilenko]

🚀 Description

This PR improves the error handling mechanisms and logging across the application, while fixing some of the errors related to refresh token handling. Also, a small test for error handling is added to the "copy diagnostic info" button, press it 5 times in a row and observe the result.

📄 Motivation and Context

#451

🧪 How Has This Been Tested?

• Web (desktop)
• Web (mobile)
• Mobile (iOS)
• Mobile (Android)
• TV (Android)
• TV (Apple)

📦 Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

✅ Checklist (copied from README)

• Squash your changes into a single clear and thoroughly descriptive commit, split changes into multiple commits only when it contributes to readability
• Reference the GitHub issue that you are contributing on in your commit title or body
• Sign your commits, as this is required by the automated GitHub PR checks
• Ensure that the changes adhere to the project code style and formatting rules by running npx eslint . and npx prettier --check ../ from the ./OwnTube.tv/ directory (without errors/warnings)
• Include links and illustrations in your pull request to make it easy to review
• Request a review by @mykhailodanilenko, @ar9708 and @mblomdahl

[Copilot]

Pull Request Overview

Improves error handling, diagnostics, and session/token refresh logic, adds customizable error page button styling, and introduces diagnostic test behavior when rapidly copying device info.

• Adds richer error propagation (including collection/query errors) and PostHog diagnostic payloads.
• Refactors auth/session refresh logic and introduces 401 response handling plus safer cleanup in diagnostics hooks.
• Adds localized strings and UI tweaks (custom button text color, diagnostic copy stress test).

Reviewed Changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
screens/Playlists/index.tsx	Passes collection error object into error UI fallback.
screens/Playlists/components/PlaylistVideosView.tsx	Avoids suppressing error state when data empty.
screens/Playlist/index.tsx	Propagates playlist video load error to VideoGrid.
screens/ChannelsScreen/index.tsx	Consolidates error handling and defers to top-level ErrorPage.
screens/ChannelCategoryScreen/index.tsx	Adds combined video/category error propagation.
screens/CategoryScreen/index.tsx	Adds error state passthrough to VideoGrid.
screens/CategoriesScreen/index.tsx	Includes collection error in error resolution logic.
public/featured-instances.json5	Enables username/password login for an instance.
locales/*.json	Adds new i18n keys for copy feedback and stress test error.
hooks/useAuthSessionSync.tsx	Async session selection with loaded-state guard.
hooks/useAppStateDiagnostics.ts	Safeguards optional subscription cleanup.
diagnostics/useCustomDiagnosticEvents.ts	Removes unsafe any cast when capturing events.
components/shared/Button.tsx	Adds optional textColor override and adjusts text color logic.
components/ErrorPage.tsx	Supports custom button styling/colors.
components/ErrorBoundary.tsx	Supplies explicit button styling/colors.
components/DeviceCapabilities/DeviceCapabilities.tsx	Adds copy feedback, press limit test throwing an error, refactors UI.
components/ChannelView.tsx	Avoids hiding component on error state.
components/CategoryView.tsx	Adds variant prop and avoids early return on error.
app/_layout.tsx	Repositions ErrorBoundary higher in component tree.
api/helpers.ts	Adds collection error aggregation and Axios error parsing utility.
api/errorHandler.ts	Adds structured diagnostics for HTTP errors.
api/axiosInstance.ts	Refines token refresh logic and adds 401 response interceptor.

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[mblomdahl]

@claude Please review.

[claude]

Claude encountered an error —— View job

Failed with exit code 128

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I'll analyze this and get back to you.

[ar9708]

Replaced by #459