fix(security): re-enable TLS verification in blockscout frontend and pin CI action SHAs

[mertcano]

Summary of Changes

Addresses security and supply-chain vulnerabilities identified during the workspace audit across arc-node (Findings F-02 and F-06).

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Key Remediations

1. Re-Enable TLS Certificate Verification (F-02 / CWE-295):

   • Commented out NODE_TLS_REJECT_UNAUTHORIZED=0 in deployments/monitoring/config-blockscout/frontend/frontend.env.
   • Prevents disabling certificate verification across the Node.js process, protecting outbound Blockscout traffic against man-in-the-middle (MITM) attacks.
   • Documented NODE_EXTRA_CA_CERTS inline as the safe alternative for corporate proxy (e.g., ZScaler) environments requiring custom root certificates.

2. Supply-Chain Integrity via Action Pinning (F-06 / CWE-829):

   • Pinned all third-party GitHub Actions in .github/workflows/ci.yml to immutable 40-character commit SHAs: - actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3 - actions-rust-lang/setup-rust-toolchain@166cdcfd11aee3cb47222f9ddb555ce30ddb9659 # v1 - taiki-e/install-action@7623a79cdfecb99d681017af368ca353d9f49bb5 # v2 - actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0 - foundry-rs/foundry-toolchain@908c540300062bd5a7e473851cdb4282204cee09 # v1 - bufbuild/buf-action@fd21066df7214747548607aaa45548ba2b9bc1ff # v1.4.0 - docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0 - docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf # v7.2.0
   • Retained semantic version comments for traceability while protecting CI runners from tag mutation attacks.

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Verification

• YAML Validation: Verified .github/workflows/ci.yml with PyYAML (syntax and schema clean).
• TLS Configuration: Re-scanned active environment variables; zero active NODE_TLS_REJECT_UNAUTHORIZED=0 instances remain.
• Formatting: Preserved POSIX Unix LF line endings across all modified files.

[github-actions]

Hi @mertcano,

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