fix: deliver linked state updates to all clients

[benedikt-bartscher]

[greptile-apps]

Greptile Summary

The PR adds a token-manager connectivity abstraction and refreshes Redis-owned socket records so shared-state updates can reach linked clients on other backend instances.

• Adds cross-instance connection checks and Redis socket-record cache refresh.
• Moves linked-client filtering into asynchronous fan-out tasks.
• Adds local, remote, stale-record, moved-owner, and Redis-error tests.

Confidence Score: 4/5

The PR is not yet safe to merge because linked updates can still be sent to a disconnected SID while local disconnect cleanup is pending.

A locally owned cached socket record is accepted without refreshing ownership, while disconnect cleanup runs asynchronously and update delivery uses that same cached SID, leaving the previously reported dropped-update race reachable.

Files Needing Attention: reflex/utils/token_manager.py, reflex/app.py

Important Files Changed

Filename	Overview
reflex/istate/shared.py	Shared-state fan-out now checks token connectivity asynchronously before modifying linked client state; the previously reported pending-disconnect race remains.
reflex/utils/token_manager.py	Adds a common connectivity API and Redis ownership refresh, but locally cached ownership is still trusted during asynchronous disconnect cleanup.
tests/units/istate/test_shared.py	Adds coverage for local filtering and cross-instance Redis fan-out.
tests/units/utils/test_token_manager.py	Adds focused coverage for local, stale foreign, moved foreign, and Redis-error connection checks.
news/6934.bugfix.md	Documents the intended cross-worker shared-state delivery fix.

_{Reviews (3): Last reviewed commit: "cubic" | Re-trigger Greptile}

[codspeed-hq]

Merging this PR will not alter performance

✅ 27 untouched benchmarks
⏩ 8 skipped benchmarks¹

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_{Comparing benedikt-bartscher:shared-state-redis-fix (b643ed8) with main (d86f167)}

Footnotes

1. 8 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[cubic-dev-ai]

All reported issues were addressed across 4 files

<sub>Reply with feedback, questions, or to request a fix.

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