refactor(validation): remove compute-budget special-casing from must_call_programs

Keep must_call_programs focused on required-program matching only.
Compute-only transaction rejection belongs to the dedicated compute-only
validation flow (PR #421), not this rule.

- Remove ComputeBudget filtering from must_call_programs runtime check
- Remove compute-budget-only config rejection for must_call_programs
- Update docs/comments and adjust config validator test expectations

Refs: PRO-1089

Author: dev-jodee

crates/lib/src/config.rs

@@ -138,7 +138,6 @@ pub struct ValidationConfig {
     #[serde(default)]
     pub max_price_staleness_slots: u64,
     /// Programs that must be called by the transaction (at least one must appear).
-    /// Transactions containing only ComputeBudget instructions are also rejected when non-empty.
     /// Each required program must also be listed in `allowed_programs`.
     /// Default: empty (no restriction).
     #[serde(default)]

crates/lib/src/validator/config_validator.rs

@@ -448,19 +448,6 @@ impl ConfigValidator {
 
         // Validate must_call_programs constraints
         if !config.validation.must_call_programs.is_empty() {
-            let compute_budget_program = solana_compute_budget_interface::id().to_string();
-
-            if config
-                .validation
-                .must_call_programs
-                .iter()
-                .all(|program| program == &compute_budget_program)
-            {
-                errors.push(
-                    "must_call_programs cannot contain only the Compute Budget program".to_string(),
-                );
-            }
-
             for program in &config.validation.must_call_programs {
                 if !config.validation.allowed_programs.contains(program) {
                     errors.push(format!(
@@ -1127,24 +1114,22 @@ mod tests {
 
     #[tokio::test]
     #[serial]
-    async fn test_validate_with_result_must_call_programs_compute_budget_only_error() {
+    async fn test_validate_with_result_must_call_programs_allows_compute_budget_program() {
         let mut config = ConfigMockBuilder::new().build();
         config.kora.cache.enabled = false;
         let compute_budget_program = solana_compute_budget_interface::id().to_string();
-        config.validation.allowed_programs = vec![compute_budget_program.clone()];
+        config.validation.allowed_programs = vec![
+            SYSTEM_PROGRAM_ID.to_string(),
+            SPL_TOKEN_PROGRAM_ID.to_string(),
+            compute_budget_program.clone(),
+        ];
         config.validation.must_call_programs = vec![compute_budget_program];
-        config.validation.price.model = PriceModel::Free;
 
         let _ = update_config(config);
 
         let rpc_client = RpcMockBuilder::new().build();
         let result = ConfigValidator::validate_with_result(&rpc_client, true).await;
-        assert!(result.is_err());
-        let errors = result.unwrap_err();
-
-        assert!(errors.iter().any(|e| {
-            e.contains("must_call_programs cannot contain only the Compute Budget program")
-        }));
+        assert!(result.is_ok());
     }
 
     #[tokio::test]

crates/lib/src/validator/transaction_validator.rs

@@ -187,21 +187,10 @@ impl TransactionValidator {
             return Ok(());
         }
 
-        let compute_budget_id = solana_compute_budget_interface::id();
-        let non_cu_instructions: Vec<_> = transaction_resolved
+        let called = transaction_resolved
             .all_instructions
             .iter()
-            .filter(|ix| ix.program_id != compute_budget_id)
-            .collect();
-
-        if non_cu_instructions.is_empty() {
-            return Err(KoraError::InvalidTransaction(
-                "Transaction contains only ComputeBudget instructions".to_string(),
-            ));
-        }
-
-        let called =
-            non_cu_instructions.iter().any(|ix| self.must_call_programs.contains(&ix.program_id));
+            .any(|ix| self.must_call_programs.contains(&ix.program_id));
         if !called {
             return Err(KoraError::InvalidTransaction(format!(
                 "Transaction must call at least one of the required programs: {:?}",

kora.toml

@@ -68,7 +68,7 @@ allowed_tokens = [
 allowed_spl_paid_tokens = []
 #allowed_spl_paid_tokens = "All"  # Allow any token to be used for payment,
 disallowed_accounts = []
-# must_call_programs = []  # At least one of these programs must be called. Each must also appear in allowed_programs. Transactions with only ComputeBudget instructions are rejected when non-empty.
+# must_call_programs = []  # At least one of these programs must be called. Each must also appear in allowed_programs.
 
 # Fee payer policy controls what actions the fee payer can perform
 #