feat: add strategy pause control

[Schlagonia]

Summary

• add setPaused(bool) with emergency-authorized pause and management-only unpause
• gate ERC4626 user flows while paused and allow emergencyWithdraw while paused or shutdown
• add pause coverage for access control, ERC4626 blocking, ERC20 share behavior, and management operations

Tests

• forge test --match-contract 'PauseTest|ShutdownTest|AccessControlTest|TokenizedStrategyLibViewsTest' -vv
• forge test -vv