unified tool dispatch: remove memory_ special case

All tools go through tools::dispatch() — no more separate
dispatch path for memory tools in the runner. The only
remaining special case is tagging memory_render results as
ConversationEntry::Memory for context deduplication, which
is a result-handling concern, not dispatch.

Co-Developed-By: Kent Overstreet <kent.overstreet@linux.dev>

src/user/runner.rs

@@ -422,6 +422,7 @@ impl Agent {
             if let Some(ref tool_calls) = msg.tool_calls {
                 if !tool_calls.is_empty() {
                     self.push_message(msg.clone());
+
                     for call in tool_calls {
                         self.dispatch_tool_call(call, None, ui_tx, &mut ds)
                             .await;
@@ -499,53 +500,7 @@ impl Agent {
             return;
         }
 
-        // Handle memory tools — needs &mut self for node tracking
+        // Dispatch through unified path
-        if call.function.name.starts_with("memory_") {
-            let result = tools::memory::dispatch(&call.function.name, &args, None);
-            let text = match &result {
-                Ok(s) => s.clone(),
-                Err(e) => format!("Error: {:#}", e),
-            };
-
-            // Disambiguate memory renders from other tool results
-            let memory_key = if result.is_ok() {
-                match call.function.name.as_str() {
-                    "memory_render" =>
-                        args.get("key").and_then(|v| v.as_str()).map(String::from),
-                    _ => None,
-                }
-            } else {
-                None
-            };
-
-            let output = tools::ToolOutput {
-                text,
-                is_yield: false,
-                images: Vec::new(),
-                model_switch: None,
-                dmn_pause: false,
-            };
-            let _ = ui_tx.send(UiMessage::ToolResult {
-                name: call.function.name.clone(),
-                result: output.text.clone(),
-            });
-            let _ = ui_tx.send(UiMessage::ToolFinished { id: call.id.clone() });
-            let mut msg = Message::tool_result(&call.id, &output.text);
-            msg.stamp();
-            if let Some(key) = memory_key {
-                self.push_entry(ConversationEntry::Memory { key, message: msg });
-            } else {
-                self.push_entry(ConversationEntry::Message(msg));
-            }
-            ds.had_tool_calls = true;
-            if output.text.starts_with("Error:") {
-                ds.tool_errors += 1;
-            }
-            
-            self.publish_context_state();
-            return;
-        }
-
         let output =
             tools::dispatch(&call.function.name, &args, &self.process_tracker).await;
 
@@ -555,7 +510,7 @@ impl Agent {
             ds.had_tool_calls = true;
         }
         if output.model_switch.is_some() {
-            ds.model_switch = output.model_switch;
+            ds.model_switch = output.model_switch.clone();
         }
         if output.dmn_pause {
             ds.dmn_pause = true;
@@ -570,11 +525,20 @@ impl Agent {
         });
         let _ = ui_tx.send(UiMessage::ToolFinished { id: call.id.clone() });
 
+        // Tag memory_render results for context deduplication
+        if call.function.name == "memory_render" && !output.text.starts_with("Error:") {
+            if let Some(key) = args.get("key").and_then(|v| v.as_str()) {
+                let mut msg = Message::tool_result(&call.id, &output.text);
+                msg.stamp();
+                self.push_entry(ConversationEntry::Memory { key: key.to_string(), message: msg });
+                self.publish_context_state();
+                return;
+            }
+        }
+
         self.push_message(Message::tool_result(&call.id, &output.text));
 
         if !output.images.is_empty() {
-            // Only one live image in context at a time — age out any
-            // previous ones to avoid accumulating ~90KB+ per image.
             self.age_out_images();
             self.push_message(Message::user_with_images(
                 "Here is the image you requested:",