Expose checkpoint state projections

[Th0rgal]

Summary

• Project checkpoint states through their carried shared state, execution env, machine state, external state, and variable store instead of default.
• This makes raw state[name]! lookup agree with checkpoint payload lookup when execution resumes after Leave/Break/Continue checkpoints.

Verification

• lake build EvmYul.Yul.StateOps
• Downstream Verity tiny Lean probe for revived checkpoint lookup passed.
• Downstream lake build Compiler.Proofs.YulGeneration.Backends.EvmYulLeanNativeHarness passed.
• Downstream lake build Compiler.Proofs.EndToEnd passed.

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Note

Low Risk
Low risk: this only changes how Checkpoint variants are projected to shared/execution/machine/external state and varstore, avoiding unintended default values during control-flow jumps.

Overview
Updates Yul State projection helpers (toSharedState, executionEnv, toMachineState, toState, store) to extract values from Checkpoint (Continue/Break/Leave) payloads instead of falling back to default.

This makes state projections and var lookups consistent when execution resumes from checkpoints, while keeping OutOfFuel behavior unchanged (still projects to default).

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