Feature deactivation on demand

[mtabasco]

Overview

This PR introduces a bitmask-based feature flags mechanism to the StrategyManager module, allowing the DAO (contract owner) to enable or disable key on-chain functionality in bulk—without a full contract redeploy.

Key benefits:

• Compact storage: Packs multiple booleans into a single uint32.
• Gas-efficient: Minimal overhead for checking and updating flags.
• Emergency control: Rapidly disable critical operations if needed.

Changes

1. New constants & storage

   uint32 private constant SLASHING_DISABLED    = 1 << 0;
   uint32 private constant WITHDRAWALS_DISABLED = 1 << 1;
   // Added `uint32 disabledFeatures` in `ProtocolStorageLib.Data`

2. DAO-only toggle

   function updateDisabledFeatures(uint32 disabledFeatures) external onlyOwner;

   • Bulk updates all feature flags in one call.

3. Runtime guards

   • checkSlashingAllowed() in slash(...) → reverts SlashingDisabled() if bit 0 set.
   • checkWithdrawalsAllowed() in withdrawal functions → reverts WithdrawalsDisabled() if bit 1 set.

4. Spec documentation

   • Added Feature Flags in StrategyManager spec outlining bit layout, purpose, and usage.

5. Test coverage

   • New unit tests ensure:
     • Slashing disabled only → slash reverts, withdrawals still work.
     • Withdrawals disabled only → withdrawal calls revert, slashing works.
     • Both disabled → both families revert.
     • Clearing flags restores functionality.

Testing

All new logic is covered in StrategyManagerTest:

• Toggle each bit individually and verify expected reverts or successes.
• Bulk toggle combinations.

Security & Governance

• Access: Only the DAO (owner) may call updateFeatureDisabledFlags.
• Bulk toggles: No per-feature transaction overhead; simpler governance process.

Future Work

• Reserve bits 2–31 for new toggles (e.g., new feature launches, global pause).

[mtabasco]

pending to adapt deployment scripts for different environments in another PR