Refactor port forward manager cleanup lifecycle

[pappz]

Replace async goroutine-based cleanup with a synchronous flow where Start runs cleanup inline after renewLoop exits. Use a stopCtx channel so GracefullyStop can pass its deadline-bounded context to Start's cleanup path. When no graceful stop occurs, Start fires cleanup in a background goroutine with a 10s timeout.

Also fix GetMapping double Lock, renewMapping referencing undefined m.mu, cleanup referencing undefined variables, remove statemanager dependency

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Quality Gate passed

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0 New issues
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0.0% Coverage on New Code
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