feat: add per-market multi-signer dispute resolution

contracts/predictify-hybrid/src/dispute_multisig.rs

@@ -0,0 +1,101 @@
+//! Per-market multi-signer dispute resolution (issue #731).
+
+use soroban_sdk::{contracttype, Address, Env, String, Symbol, Vec};
+use crate::err::Error;
+
+#[contracttype]
+#[derive(Clone, Debug)]
+pub struct MultiSigDisputeState {
+    pub market_id: Symbol,
+    pub threshold: u32,
+    pub signers: Vec<Address>,
+    pub approvals: Vec<Address>,
+    pub proposed_outcome: String,
+}
+
+pub struct DisputeMultiSig;
+
+impl DisputeMultiSig {
+    fn key(env: &Env, market_id: &Symbol) -> (Symbol, Symbol) {
+        (Symbol::new(env, "dms"), market_id.clone())
+    }
+
+    pub fn configure(
+        env: &Env,
+        admin: Address,
+        market_id: Symbol,
+        signers: Vec<Address>,
+        threshold: u32,
+        proposed_outcome: String,
+    ) -> Result<(), Error> {
+        admin.require_auth();
+        if signers.is_empty() { return Err(Error::InvalidInput); }
+        if threshold == 0 || threshold > signers.len() { return Err(Error::InvalidInput); }
+        let state = MultiSigDisputeState {
+            market_id: market_id.clone(), threshold, signers,
+            approvals: Vec::new(env), proposed_outcome,
+        };
+        env.storage().instance().set(&Self::key(env, &market_id), &state);
+        Ok(())
+    }
+
+    pub fn approve(env: &Env, signer: Address, market_id: Symbol) -> Result<bool, Error> {
+        signer.require_auth();
+        let key = Self::key(env, &market_id);
+        let mut state: MultiSigDisputeState = env.storage().instance().get(&key).ok_or(Error::MarketNotFound)?;
+        if !state.signers.iter().any(|s| s == signer) { return Err(Error::Unauthorized); }
+        if state.approvals.iter().any(|s| s == signer) { return Err(Error::InvalidState); }
+        state.approvals.push_back(signer);
+        let reached = state.approvals.len() >= state.threshold;
+        if reached { env.storage().instance().remove(&key); } else { env.storage().instance().set(&key, &state); }
+        Ok(reached)
+    }
+
+    pub fn get_state(env: &Env, market_id: &Symbol) -> Option<MultiSigDisputeState> {
+        env.storage().instance().get(&Self::key(env, market_id))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use soroban_sdk::{testutils::Address as _, Env};
+
+    #[test]
+    fn test_threshold_one_resolves_on_single_approval() {
+        let env = Env::default(); env.mock_all_auths();
+        let admin = Address::generate(&env);
+        let s = Address::generate(&env);
+        let mid = Symbol::new(&env, "mkt1");
+        DisputeMultiSig::configure(&env, admin, mid.clone(), soroban_sdk::vec![&env, s.clone()], 1, String::from_str(&env, "YES")).unwrap();
+        assert!(DisputeMultiSig::approve(&env, s, mid.clone()).unwrap());
+        assert!(DisputeMultiSig::get_state(&env, &mid).is_none());
+    }
+
+    #[test]
+    fn test_two_of_two_requires_both() {
+        let env = Env::default(); env.mock_all_auths();
+        let admin = Address::generate(&env);
+        let s1 = Address::generate(&env); let s2 = Address::generate(&env);
+        let mid = Symbol::new(&env, "mkt2");
+        DisputeMultiSig::configure(&env, admin, mid.clone(), soroban_sdk::vec![&env, s1.clone(), s2.clone()], 2, String::from_str(&env, "NO")).unwrap();
+        assert!(!DisputeMultiSig::approve(&env, s1, mid.clone()).unwrap());
+        assert!(DisputeMultiSig::approve(&env, s2, mid.clone()).unwrap());
+    }
+
+    #[test]
+    fn test_threshold_zero_rejected() {
+        let env = Env::default(); env.mock_all_auths();
+        let admin = Address::generate(&env); let s = Address::generate(&env);
+        assert!(DisputeMultiSig::configure(&env, admin, Symbol::new(&env, "m"), soroban_sdk::vec![&env, s], 0, String::from_str(&env, "X")).is_err());
+    }
+
+    #[test]
+    fn test_unauthorised_signer_rejected() {
+        let env = Env::default(); env.mock_all_auths();
+        let admin = Address::generate(&env); let auth = Address::generate(&env); let intruder = Address::generate(&env);
+        let mid = Symbol::new(&env, "mkt3");
+        DisputeMultiSig::configure(&env, admin, mid.clone(), soroban_sdk::vec![&env, auth], 1, String::from_str(&env, "YES")).unwrap();
+        assert!(DisputeMultiSig::approve(&env, intruder, mid).is_err());
+    }
+}

contracts/predictify-hybrid/src/lib.rs

@@ -7591,4 +7591,4 @@ mod tests {
             assert!(guard.consumed() == 0); // No instructions consumed yet in test host
         });
     }
-}
+}mod dispute_multisig;