feat: Add bridge E2E test suite with oracle-based cross-chain minting

[ByteYue]

Description

feat: Add bridge E2E test suite with oracle-based cross-chain minting

• Add anvil_manager.py for Anvil process lifecycle and forge contract deployment
• Add bridge_utils.py for web3.py bridge interactions and event polling
• Add gravity_e2e/cluster_test_cases/bridge/ test suite with 10-min continuous loop
• Configure single-node cluster with oracle + bridge relayer integration
• Fix relayer_config timing by stopping/restarting nodes after contract deployment
• Ensure cluster scripts always pull latest code (gravity_bench, genesis contracts)

How Has This Been Tested?

Key Areas to Review

Type of Change

• New feature
• Bug fix
• Breaking change
• Performance improvement
• Refactoring
• Dependency update
• Documentation update
• Tests

Which Components or Systems Does This Change Impact?

• Validator Node
• Consensus
• EVM Runtime
• Gravity SDK Core
• CLI Tools
• E2E Tests
• Documentation
• Other (specify)

Checklist

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes