feat: add VaultV2.depositFor() for Trial Market Program treasury seeding

contracts/v2/VaultV2.sol

@@ -44,6 +44,9 @@ contract VaultV2 is ReentrancyGuard {
     address public admin;
     bool public paused;
 
+    /// @notice Platform treasury address — authorized to call depositFor()
+    address public treasury;
+
     /// @notice Internal ledger balances
     mapping(address => uint256) public balances;
 
@@ -80,12 +83,14 @@ contract VaultV2 is ReentrancyGuard {
     event Paused(address indexed admin);
     event Unpaused(address indexed admin);
     event AdminTransferred(address indexed oldAdmin, address indexed newAdmin);
+    event TreasuryUpdated(address indexed oldTreasury, address indexed newTreasury);
 
     // ============================================================
     // Errors
     // ============================================================
 
     error NotAdmin();
+    error NotTreasury();
     error VaultPaused();
     error InsufficientBalance();
     error InsufficientSplitReserve();
@@ -128,6 +133,11 @@ contract VaultV2 is ReentrancyGuard {
         _;
     }
 
+    modifier onlyTreasury() {
+        if (msg.sender != treasury) revert NotTreasury();
+        _;
+    }
+
     // ============================================================
     // Constructor
     // ============================================================
@@ -157,6 +167,31 @@ contract VaultV2 is ReentrancyGuard {
         emit LedgerTransfer(address(0), msg.sender, amount, LedgerReason.UserDeposit);
     }
 
+    /**
+     * @notice Deposit USDC on behalf of a recipient (platform treasury only)
+     * @param recipient Address whose vault balance is credited
+     * @param amount USDC amount (6 decimals)
+     * @dev Used by the Trial Market Program: treasury tops up the creator's vault
+     *      balance so the factory can pull the $30 seed via pullForNewMarket().
+     *      Requires treasury to be configured via setTreasury() by admin.
+     *      See docs/TRIAL_MARKET_PROGRAM.md §8.1
+     */
+    function depositFor(address recipient, uint256 amount)
+        external
+        nonReentrant
+        whenNotPaused
+        onlyTreasury
+    {
+        if (amount == 0) revert ZeroAmount();
+        if (recipient == address(0)) revert ZeroAddress();
+
+        usdc.safeTransferFrom(msg.sender, address(this), amount);
+        balances[recipient] += amount;
+        totalBalances += amount;
+
+        emit LedgerTransfer(address(0), recipient, amount, LedgerReason.PlatformSeed);
+    }
+
     /**
      * @notice Withdraw USDC from the vault
      * @param amount USDC amount to withdraw
@@ -381,6 +416,12 @@ contract VaultV2 is ReentrancyGuard {
         emit TrustedFactoryUpdated(_factory, false);
     }
 
+    function setTreasury(address _treasury) external onlyAdmin {
+        address old = treasury;
+        treasury = _treasury;
+        emit TreasuryUpdated(old, _treasury);
+    }
+
     function setExchange(address _exchange) external onlyAdmin {
         exchange = _exchange;
     }

contracts/v2/interfaces/Types.sol

@@ -55,7 +55,8 @@ enum LedgerReason {
     AccumulateFee,
     WithdrawFeePool,
     TransferBetween,
-    MarketInitLiquidity
+    MarketInitLiquidity,
+    PlatformSeed          // Treasury deposits seed on behalf of trial market creator
 }
 
 // ============================================================

test/VaultV2.t.sol

@@ -287,4 +287,148 @@ contract VaultV2Test is Test {
         uint256 accounting = vault.totalBalances() + vault.splitReserve() + vault.feePool();
         assertEq(usdcBal, accounting, "invariant: USDC should exactly match accounting");
     }
+
+    // ============================================================
+    // depositFor — Trial Market Program treasury seeding
+    // ============================================================
+
+    address public treasury = makeAddr("treasury");
+
+    function _setupTreasury() internal {
+        // Admin sets the treasury address
+        vm.prank(admin);
+        vault.setTreasury(treasury);
+
+        // Treasury mints and approves USDC
+        usdc.mint(treasury, 1_000_000_000); // 1000 USDC
+        vm.prank(treasury);
+        usdc.approve(address(vault), type(uint256).max);
+    }
+
+    function test_depositFor_creditsRecipient() public {
+        _setupTreasury();
+
+        uint256 seed = 30_000_000; // $30
+        vm.prank(treasury);
+        vault.depositFor(bob, seed);
+
+        assertEq(vault.balances(bob), seed);
+        assertEq(vault.totalBalances(), seed);
+        assertEq(usdc.balanceOf(address(vault)), seed);
+    }
+
+    function test_depositFor_invariantHolds() public {
+        _setupTreasury();
+
+        vm.prank(treasury);
+        vault.depositFor(bob, 30_000_000);
+
+        uint256 usdcBal = usdc.balanceOf(address(vault));
+        uint256 accounting = vault.totalBalances() + vault.splitReserve() + vault.feePool();
+        assertEq(usdcBal, accounting, "invariant must hold after depositFor");
+    }
+
+    function test_depositFor_allowsSubsequentPullForNewMarket() public {
+        _setupTreasury();
+
+        // Treasury tops up bob's balance ($30 seed)
+        vm.prank(treasury);
+        vault.depositFor(bob, 30_000_000);
+
+        // Factory pulls seed from bob to market (simulates trial market creation)
+        vm.prank(factory);
+        vault.pullForNewMarket(bob, market, 30_000_000);
+
+        assertEq(vault.balances(bob), 0);
+        assertEq(vault.balances(market), 30_000_000);
+        // totalBalances unchanged (zero-sum pullForNewMarket)
+        assertEq(vault.totalBalances(), 30_000_000);
+    }
+
+    function test_depositFor_revertsIfNotTreasury() public {
+        _setupTreasury();
+
+        vm.prank(alice); // not treasury
+        vm.expectRevert(VaultV2.NotTreasury.selector);
+        vault.depositFor(bob, 30_000_000);
+    }
+
+    function test_depositFor_revertsIfTreasuryNotSet() public {
+        // No setTreasury call — treasury is address(0)
+        usdc.mint(address(this), 30_000_000);
+        usdc.approve(address(vault), 30_000_000);
+
+        vm.expectRevert(VaultV2.NotTreasury.selector);
+        vault.depositFor(bob, 30_000_000);
+    }
+
+    function test_depositFor_revertsZeroAmount() public {
+        _setupTreasury();
+
+        vm.prank(treasury);
+        vm.expectRevert(VaultV2.ZeroAmount.selector);
+        vault.depositFor(bob, 0);
+    }
+
+    function test_depositFor_revertsZeroAddress() public {
+        _setupTreasury();
+
+        vm.prank(treasury);
+        vm.expectRevert(VaultV2.ZeroAddress.selector);
+        vault.depositFor(address(0), 30_000_000);
+    }
+
+    function test_depositFor_revertsWhenPaused() public {
+        _setupTreasury();
+
+        vm.prank(admin);
+        vault.pause();
+
+        vm.prank(treasury);
+        vm.expectRevert(VaultV2.VaultPaused.selector);
+        vault.depositFor(bob, 30_000_000);
+    }
+
+    // ============================================================
+    // setTreasury
+    // ============================================================
+
+    function test_setTreasury_byAdmin() public {
+        address newTreasury = makeAddr("newTreasury");
+
+        vm.prank(admin);
+        vault.setTreasury(newTreasury);
+
+        assertEq(vault.treasury(), newTreasury);
+    }
+
+    function test_setTreasury_emitsEvent() public {
+        address newTreasury = makeAddr("newTreasury");
+
+        vm.prank(admin);
+        vm.expectEmit(true, true, false, false);
+        emit VaultV2.TreasuryUpdated(address(0), newTreasury);
+        vault.setTreasury(newTreasury);
+    }
+
+    function test_setTreasury_revertsIfNotAdmin() public {
+        vm.prank(alice);
+        vm.expectRevert(VaultV2.NotAdmin.selector);
+        vault.setTreasury(makeAddr("treasury"));
+    }
+
+    function test_setTreasury_canClearTreasury() public {
+        _setupTreasury();
+
+        // Clear treasury (set to zero)
+        vm.prank(admin);
+        vault.setTreasury(address(0));
+
+        assertEq(vault.treasury(), address(0));
+
+        // depositFor should now revert (msg.sender != address(0))
+        vm.prank(treasury);
+        vm.expectRevert(VaultV2.NotTreasury.selector);
+        vault.depositFor(bob, 30_000_000);
+    }
 }