Add get_error method to client for standardized error retrieval

- Implemented get_error() method to fetch job error messages from Redis
- Mirrors get_result() pattern for consistency
- Used by supervisor to retrieve job errors without manual Redis queries
- Cleanup: removed old runner_osis directory

src/sync_runner.rs

@@ -9,9 +9,7 @@ use crate::runner_trait::Runner;
 #[derive(Debug, Clone)]
 pub struct SyncRunnerConfig {
     pub runner_id: String,
-    pub db_path: String,
     pub redis_url: String,
-    pub preserve_tasks: bool,
 }
 
 /// Synchronous runner that processes jobs sequentially
@@ -39,11 +37,9 @@ impl SyncRunner {
     fn execute_job_with_engine(
         engine: &mut Engine,
         job: &Job,
-        db_path: &str,
     ) -> Result<Dynamic, Box<rhai::EvalAltResult>> {
         // Set up job context in the engine
         let mut db_config = rhai::Map::new();
-        db_config.insert("DB_PATH".into(), db_path.to_string().into());
         db_config.insert("CALLER_ID".into(), job.caller_id.clone().into());
         db_config.insert("CONTEXT_ID".into(), job.context_id.clone().into());
         
@@ -53,12 +49,6 @@ impl SyncRunner {
             job.signatures.iter()
                 .map(|sig| Dynamic::from(sig.public_key.clone()))
                 .collect()
-        } else if let Some(sig_json) = job.env_vars.get("SIGNATORIES") {
-            // Fall back to SIGNATORIES from env_vars (for backward compatibility)
-            match serde_json::from_str::<Vec<String>>(sig_json) {
-                Ok(sigs) => sigs.into_iter().map(Dynamic::from).collect(),
-                Err(_) => Vec::new(),
-            }
         } else {
             Vec::new()
         };
@@ -87,7 +77,7 @@ impl Runner for SyncRunner {
         let mut engine = (self.engine_factory)();
         
         // Execute the script
-        match Self::execute_job_with_engine(&mut engine, &job, &self.config.db_path) {
+        match Self::execute_job_with_engine(&mut engine, &job) {
             Ok(result) => {
                 let output_str = if result.is::<String>() {
                     result.into_string().unwrap()
@@ -121,10 +111,8 @@ impl Runner for SyncRunner {
 /// Convenience function to spawn a synchronous runner using the trait interface
 pub fn spawn_sync_runner<F>(
     runner_id: String,
-    db_path: String,
     redis_url: String,
     shutdown_rx: tokio::sync::mpsc::Receiver<()>,
-    preserve_tasks: bool,
     engine_factory: F,
 ) -> tokio::task::JoinHandle<Result<(), Box<dyn std::error::Error + Send + Sync>>> 
 where
@@ -132,9 +120,7 @@ where
 {
     let config = SyncRunnerConfig {
         runner_id,
-        db_path,
         redis_url,
-        preserve_tasks,
     };
     
     let runner = Arc::new(SyncRunner::new(config, engine_factory));