fix: normalize episodic/compact roles to system in all LLM providers

src/llm/bedrock.rs

@@ -59,7 +59,17 @@ impl BedrockClient {
         let mut messages_limited = Vec::new();
         if let Some(msg_array) = raw_messages.as_array() {
             for msg in msg_array {
-                messages_limited.push(msg.clone());
+                let role = msg.get("role").and_then(|r| r.as_str()).unwrap_or("user");
+                let normalized_role = match role {
+                    "user" | "assistant" | "system" | "developer" | "tool" => role,
+                    "episodic" | "compact" => "system",
+                    _ => "user",
+                };
+                let mut new_msg = msg.clone();
+                if let Some(obj) = new_msg.as_object_mut() {
+                    obj.insert("role".to_string(), serde_json::json!(normalized_role));
+                }
+                messages_limited.push(new_msg);
             }
         }
         Value::Array(messages_limited)

src/llm/glm.rs

@@ -207,8 +207,13 @@ impl LLMProvider for GLMClient {
                     let role = m.get("role")?.as_str()?;
                     let content = m.get("content")?.as_str()?;
                     let sanitized = Self::sanitize_utf8(content);
+                    let normalized_role = match role {
+                        "user" | "assistant" | "system" | "tool" => role,
+                        "episodic" | "compact" => "system",
+                        _ => "user",
+                    };
                     Some(GLMMessage {
-                        role: role.to_string(),
+                        role: normalized_role.to_string(),
                         content: Some(sanitized),
                         tool_calls: None,
                     })

src/llm/kimi.rs

@@ -211,8 +211,13 @@ impl LLMProvider for KimiClient {
                     let role = m.get("role")?.as_str()?;
                     let content = m.get("content")?.as_str()?;
                     let sanitized = Self::sanitize_utf8(content);
+                    let normalized_role = match role {
+                        "user" | "assistant" | "system" | "tool" => role,
+                        "episodic" | "compact" => "system",
+                        _ => "user",
+                    };
                     Some(KimiMessage {
-                        role: role.to_string(),
+                        role: normalized_role.to_string(),
                         content: Some(sanitized),
                         tool_calls: None,
                     })

src/llm/vertex.rs

@@ -231,8 +231,10 @@ impl VertexClient {
                 let content = msg.get("content").and_then(|c| c.as_str()).unwrap_or("");
                 
                 let gemini_role = match role {
+                    "user" => "user",
                     "assistant" => "model",
-                    "system" => "user", // Gemini doesn't have system role in 'contents' by default, often wrapped in systemInstruction
+                    "system" | "episodic" | "compact" => "user",
+                    "tool" => "user",
                     _ => "user",
                 };