fix(safe): close transaction-shape and guard validation gaps [ENG-4235]

[makemake-kbo]

Summary

• make the shared Safe protection contracts the single maintained source while preserving example imports
• enforce CALL MultiSend outer-value and actual allowance-owner semantics, and reject transient cumulative allowance grants above policy caps
• align deployment registry validation with runtime 50k-gas, exact-return, canonical-bool, and future-block rules
• document tested module-set limits and add regressions for CALL batches, transient approvals, malformed/slow registries, and future credible blocks

Validation

• FOUNDRY_PROFILE=safe pcl test (2 passed)
• targeted Safe PCL regressions for transient grants, CALL owner semantics, and outer value (3 passed)
• FOUNDRY_PROFILE=safe-guard forge test --offline --match-path test/protection/safe/integration/CredibleSafeGuardScripts.t.sol (18 passed)
• forge fmt --check

Linear: ENG-4235

[linear-code]

ENG-4235

[lean-apple]

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