feat(dao-config): Phase 4 prerequisite fields + ScriptRefs

DaoConfig gains optional fields for Phase 4 (proposal_create) work:
- proposal_addr        — proposal validator address (bech32)
- stake_st_policy      — StakeST minting policy id (56 hex)
- proposal_st_policy   — ProposalST minting policy id (56 hex)
- script_refs          — cached reference UTxO refs for each Agora script
                         (governor / stake / proposal / treasury validators
                         + stake_st / proposal_st minting policies)

All fields optional with serde defaults so existing configs keep loading.
Will be populated by upcoming `dao_discover_scripts` MCP tool that audits
on-chain state under a known governor_addr.

Test fixture also corrected: stakes_addr now uses Sulkta's real per-DAO
parameterized stake-validator address (`addr1w8msu7p...`) instead of the
shared MLabs deployer (`addr1w9gexmeunzsy...`) — matches audit findings.

aldabra-mcp dao_register tool initializes new optionals to None so
DaoConfig construction stays explicit.

crates/aldabra-dao/src/config.rs

@@ -107,6 +107,54 @@ pub struct DaoConfig {
     /// Cardano network this DAO lives on.
     #[serde(default)]
     pub network: DaoNetwork,
+
+    // ─── Phase 4 prerequisites — populated by `dao_discover_scripts` ─────────
+    //
+    // All optional: existing configs registered before Phase 4 still load.
+    // The dao_discover_scripts MCP tool fills these in by inspecting on-chain
+    // state at the governor / stakes / treasury addresses.
+
+    /// Proposal validator address (bech32). Where new proposal UTxOs land.
+    /// Different from stakes_addr / governor_addr — separate parameterized
+    /// validator. Discoverable from any tx that created a proposal.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proposal_addr: Option<String>,
+
+    /// StakeST minting policy id (56 hex chars). Mints exactly one
+    /// "stake state thread" token per stake; the asset_name on the token
+    /// equals the stake validator's script hash.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub stake_st_policy: Option<String>,
+
+    /// ProposalST minting policy id (56 hex chars). Mints one token per
+    /// proposal with empty asset name.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proposal_st_policy: Option<String>,
+
+    /// Reference UTxOs for each Agora script (so we don't re-discover on
+    /// every tx). Stored as `txhash#index` strings. Optional — falls back
+    /// to a lookup at use time when absent.
+    #[serde(default)]
+    pub script_refs: ScriptRefs,
+}
+
+/// Cached UTxO references for the parameterized Agora scripts. Populated by
+/// [`dao_discover_scripts`], consumed by Phase 4 builders so each tx can
+/// cite reference inputs without a fresh chain query.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+pub struct ScriptRefs {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub governor_validator: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub stake_validator: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proposal_validator: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub treasury_validator: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub stake_st_policy: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub proposal_st_policy: Option<String>,
 }
 
 impl DaoConfig {
@@ -315,7 +363,7 @@ mod tests {
             name: name.to_string(),
             description: Some("test".into()),
             governor_addr: "addr1w8v73wfrru7smn738k6c5xafqvl2tgsvct7dtztc4jwlf4c35jnmy".into(),
-            stakes_addr: "addr1w9gexmeunzsykesf42d4eqet5yvzeap6trjnflxqtkcf66g5740fw".into(),
+            stakes_addr: "addr1w8msu7psehjlcu5glzjgjtq53m4mk75c9d2p8hfjwyknmfqskkah8".into(),
             treasury_addr: "addr1wx2xrpft9f97ggz4u5yrkev4u340fzfsrqama95kp8l2v6qll696y".into(),
             gov_token_policy: "9c4bd4a90cdb73d9ff681215ecf7dea9fb183d916d30487d17098e05".into(),
             gov_token_name_hex: "546572726170696e".into(),
@@ -326,6 +374,10 @@ mod tests {
             treasury_ref_config:
                 "d9a1cdac8d196ad9303e0faedba992ff31f5bc2186740c362686cfad".into(),
             network: DaoNetwork::Mainnet,
+            proposal_addr: None,
+            stake_st_policy: None,
+            proposal_st_policy: None,
+            script_refs: ScriptRefs::default(),
         }
     }
 

crates/aldabra-mcp/src/tools.rs

@@ -30,7 +30,7 @@ use std::sync::Arc;
 
 use aldabra_chain::{ChainBackend, KoiosClient};
 use aldabra_dao::agora::stake::Credential as DaoCredential;
-use aldabra_dao::config::{DaoConfig, DaoNetwork, DaoStore};
+use aldabra_dao::config::{DaoConfig, DaoNetwork, DaoStore, ScriptRefs};
 use aldabra_dao::reader::{DaoReader, KoiosDaoReader};
 use aldabra_core::plutus_cost_models::PLUTUS_V3_COST_MODEL_PREPROD;
 use aldabra_core::{
@@ -1340,6 +1340,12 @@ impl WalletService {
                 Some("preview") => DaoNetwork::Preview,
                 _ => DaoNetwork::Mainnet,
             },
+            // Optional discovery fields — populated by `dao_discover_scripts`
+            // after registration.
+            proposal_addr: None,
+            stake_st_policy: None,
+            proposal_st_policy: None,
+            script_refs: ScriptRefs::default(),
         };
         self.inner
             .dao_store