Implement Multi-Signature Governance System

[am-miracle]

Issue:

The VertixGovernance contract uses OwnableUpgradeable with a single owner, creating a centralization risk.

Problems:

• A single owner can change all critical parameters
• No multi-signature protection
• No timelock mechanism

Recommendations:

• Implement multi-signature wallet (Gnosis Safe)
• Add timelock contract for parameter changes
• Add emergency pause functionality with multi-sig

Modify Existing Contract: VertixGovernance.sol

• Replace OwnableUpgradeable with multi-sig integration
• Add timelock mechanism for parameter changes
• Add emergency pause functionality
• Run forge build --sizes if the contract exceeds 24576 bytes split the contract to VertixMultiSigGovernance.sol and VertixTimelock.sol

Acceptance Criteria:

• Multi-sig wallet integration working with Gnosis Safe
• Timelock mechanism for all governance parameter changes
• Emergency pause functionality with multi-sig approval
• All existing governance functions migrated to multi-sig
• Comprehensive testing of multi-sig workflows
• Documentation for multi-sig operations