[Web] Subscription & Apollo error handling — silent failures, swallowed errors

[Flegma]

Summary

GraphQL subscription errors are logged but not recovered from, and Apollo error hook swallows certain errors.

Findings

• MatchLobbyStore — subscription errors logged with console.error but no recovery or retry.
• apollo.client.ts — early return on auth errors prevents other error handling from running.

Impact

Broken subscriptions cause stale data without notification. Some errors neither logged nor displayed.

Suggested Fix

Add subscription retry logic with backoff. Restructure Apollo error hook to process all error types.

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Related Issues (Error Handling Pattern)

• [API] Swallowed async errors — Discord setup, Redis subs, job queues, unhandled rejections #376 — [API] Swallowed async errors
• [Web] Subscription & Apollo error handling — silent failures, swallowed errors #389 — [Web] Subscription & Apollo error handling
• [Game Server] Config download failure, silent deserialization, swallowed stack traces #400 — [Game Server] Config download & swallowed exceptions
• [Connector] Swallowed promises in Redis/system/demos & demo upload file deletion race #410 — [Connector] Swallowed promises & demo upload race