feat(contract): add on-chain proposal voting system

contracts/contracts/group_treasury/src/lib.rs

@@ -89,4 +89,4 @@ impl GroupTreasuryContract {
 
         TokenClient::new(&env, &token_id).balance(&env.current_contract_address())
     }
-}
+}

contracts/contracts/group_treasury/src/storage.rs

@@ -16,4 +16,4 @@ pub struct DepositEvent {
 pub struct WithdrawEvent {
     pub to: Address,
     pub amount: i128,
-}
+}

contracts/contracts/group_treasury/src/test.rs

@@ -173,4 +173,4 @@ fn test_deposit_zero_panics() {
     let (contract_id, _token_id, _admin, member) = setup(&env);
     let client = GroupTreasuryContractClient::new(&env, &contract_id);
     client.deposit(&member, &0);
-}
+}

contracts/contracts/group_treasury/src/token_interface.rs

@@ -5,4 +5,4 @@ use soroban_sdk::{contractclient, Address, Env};
 pub trait TokenInterface {
     fn transfer(env: Env, from: Address, to: Address, amount: i128);
     fn balance(env: Env, id: Address) -> i128;
-}
+}

contracts/contracts/proposals/src/lib.rs

@@ -262,4 +262,4 @@ impl ProposalsContract {
     }
 }
 
-mod test;
+mod test;

contracts/contracts/proposals/src/storage.rs

@@ -0,0 +1,45 @@
+use soroban_sdk::{contracttype, Address, String};
+
+#[contracttype]
+#[derive(Clone)]
+pub struct Proposal {
+    pub proposer: Address,
+    pub description: String,
+    pub amount: i128,
+    pub recipient: Address,
+    pub yes_votes: u32,
+    pub no_votes: u32,
+    /// Unix timestamp (seconds) when the voting period closes.
+    pub end_time: u64,
+    pub executed: bool,
+}
+
+#[contracttype]
+pub enum DataKey {
+    Admin,
+    Treasury,
+    NextId,
+    Proposal(u32),
+    /// Tracks whether a given voter has already voted on a proposal.
+    Voted(u32, Address),
+}
+
+#[contracttype]
+pub struct ProposalCreatedEvent {
+    pub id: u32,
+    pub proposer: Address,
+    pub amount: i128,
+}
+
+#[contracttype]
+pub struct VoteCastEvent {
+    pub proposal_id: u32,
+    pub voter: Address,
+    pub approve: bool,
+}
+
+#[contracttype]
+pub struct ProposalExecutedEvent {
+    pub proposal_id: u32,
+    pub passed: bool,
+}

contracts/contracts/proposals/src/test.rs

@@ -176,4 +176,4 @@ fn create_with_past_expiry_panics() {
     // expires_at == now → not in the future → panic.
     let desc = String::from_str(&env, "x");
     client.create_proposal(&alice, &desc, &env.ledger().timestamp());
-}
+}

contracts/contracts/proposals/src/treasury_interface.rs

@@ -0,0 +1,7 @@
+use soroban_sdk::{contractclient, Address, Env};
+
+/// Minimal interface for calling the group treasury contract.
+#[contractclient(name = "TreasuryClient")]
+pub trait TreasuryInterface {
+    fn withdraw(env: Env, to: Address, amount: i128);
+}