[Backend] Refactor Redis coordination into a safe concurrency foundation

[Solomonsolomonsolomon]

Improve locking, ownership semantics, TTL extension, cleanup, and instrumentation for Redis-backed coordination used by cache, retries, and workflow control paths.nn- Priority: Mediumn- Area: Infrastructure / Reliabilityn- Advanced Scope: distributed coordination semantics, lock correctness, infra hardening

[NeduTheDev1]

@NeduTheDev1 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Please assign to me maintainer i can get it done no issues

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[newmattock]

@newmattock has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I would love to work on this issue.

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[king-aj-the-first]

@king-aj-the-first has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hii, i'd like to work on this issue

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[onlyeugene]

@onlyeugene has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

As a fullstack developer with 4 years experience working on a project like this is something i have done in the past and i will like to be assigned this issue to work on.

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[devmasalati]

@devmasalati has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

hi maintainer, i'm a full stack developer with years of experience. i would love to work on this issue. kindly assign

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