interfaces: add ISendEarnRewards (IERC4626 + IAccessControl)

[youngkidwarrior]

Why:
Provide a stable interface for integrators mirroring SendEarn-style
interfaces, exposing ERC4626 surface, events, CFA policy getters, and
helper views used by tests.

Test plan:

• bunx hardhat compile
• Reference in downstream code as needed: contracts/interfaces/ISendEarnRewards.sol

[youngkidwarrior]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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• interfaces: add ISendEarnRewards (IERC4626 + IAccessControl) #38 👈 (View in Graphite)
• rewards: depositVaultShares pre-NAV; add tests #32
• Tests: prepare for ERC4626 composability (NAV-based); remove 1:1 assumptions #37
• Tests: v2 routing, single-vault withdraw, totalAssets view, transfer re-attribution #36
• Add ERC4626 v2 tests (routing, transfers, no-loop withdraws) #35
• Add v2 ERC4626 aggregator spec (no-loop withdraws) #34
• chore: propagate refactor from refactor_rename_rewardsaggregator_-_sendearnrewards_bubble_erc4626_hooks_factory-gated_join_flow (886f744) #33
• Update wrapper cache for anvil (845337) #23 : 1 other dependent PR (#13 )
• Add UNDERLYING_ADDRESS override for wrapper #17
• Wire anvil-deploy to wrapper script; set signer #9 : 1 other dependent PR (#10 )
• Test wrapper metadata and upgrade/downgrade #8
• Align viem calls and env discovery in tests #26 : 1 other dependent PR (#27 )
• Ensure hardfork=cancun on hardhat network #25
• Add test/type dependencies and refresh bun.lock #24
• Add CFAv1Forwarder field (optional) #12
• Add Superfluid config and deployments scaffold #6 : 1 other dependent PR (#7 )
• Remove legacy lockbox code; rename Tilt resource #5
• Rename package name #3 : 1 other dependent PR (#4 )
• Scaffold project from send-token-upgrade #2
• Initialize README for SuperToken wrapper #1
• main

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