fix: validate Shasta grandparent base fee

[smtmfft]

Summary

• port the Shasta grandparent/base-fee validation fix from the hotfix branch to main
• require and bind the L2 grandparent header before using it for first-block Shasta base-fee validation
• run Shasta base-fee validation after manifest selection so default-manifest fallback cannot skip it
• include dev fork env values in SGX manifests so devnet/mainnet builds use the same image measurement path
• bump gaiko to 47944ca (taikoxyz/gaiko#31) to remove committed enclave signing material

Test Plan

• cargo fmt -p raiko-lib -- --check
• cargo test -p raiko-lib -- --nocapture
• git diff --check origin/main...HEAD
• checked gaiko@47944ca does not contain docker/enclave-key.pem or PEM private-key material

[Copilot]

Pull request overview

Ports the Shasta grandparent/base-fee validation hotfix to main, tightening first-block base-fee validation by ensuring the L2 grandparent header linkage is verified and by running validation after manifest selection so fallback manifests can’t bypass it. Also updates SGX Gramine manifest templates to carry additional dev fork env bindings for consistent enclave measurement paths across build modes.

Changes:

• Move Shasta base-fee validation to occur after protocol/default manifest selection in Shasta transaction generation.
• Strengthen Shasta base-fee validation by requiring a correctly linked L2 grandparent header (reject missing/mismatched grandparent).
• Add missing dev fork env bindings to SGX Gramine manifest templates.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
provers/sgx/config/sgx-guest.local.manifest.template	Adds DEV_SHASTA_TIMESTAMP env binding for local SGX guest manifest parity.
provers/sgx/config/sgx-guest.docker.manifest.template	Adds dev fork env bindings for Docker SGX guest manifest (noted inconsistency to address).
lib/src/utils/shasta.rs	Runs Shasta base-fee validation after manifest selection (default fallback can’t skip validation).
lib/src/utils/shasta_rules.rs	Requires/validates L2 grandparent linkage when computing first-block Shasta base fee; adds targeted tests.

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