Complete walkthrough system with VSCode IPC integration

- Add base_uri field to ResolvedWalkthrough structure
- Implement present_walkthrough IPC method for VSCode communication
- Add Debug derives to all resolved types for proper logging
- Full end-to-end walkthrough processing: MCP tool → Dialect execution → VSCode
- AI assistants can now send walkthroughs with embedded Dialect programs
- System processes all sections and sends resolved structure to VSCode extension

Author: nikomatsakis

server/src/ide.rs

@@ -297,7 +297,7 @@ pub enum ResolvedLocation {
 }
 
 /// The fully normalized struct that we send over IPC.
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Debug)]
 pub struct ResolvedComment {
     pub locations: Vec<FileRange>,
     pub icon: Option<String>,
@@ -403,7 +403,7 @@ pub struct Action {
     pub tell_agent: Option<String>,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Debug)]
 pub struct ResolvedAction {
     pub button: String,
     pub tell_agent: Option<String>,
@@ -428,15 +428,16 @@ impl<U: IpcClient> DialectFunction<U> for Action {
 
 /// Resolved walkthrough types for IPC communication with VSCode extension
 
-#[derive(Serialize)]
+#[derive(Serialize, Debug)]
 pub struct ResolvedWalkthrough {
     pub introduction: Option<Vec<ResolvedWalkthroughElement>>,
     pub highlights: Option<Vec<ResolvedWalkthroughElement>>,
     pub changes: Option<Vec<ResolvedWalkthroughElement>>,
     pub actions: Option<Vec<ResolvedWalkthroughElement>>,
+    pub base_uri: String,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Debug)]
 #[serde(untagged)]
 pub enum ResolvedWalkthroughElement {
     /// Plain markdown text

server/src/ipc.rs

@@ -180,6 +180,40 @@ impl IPCCommunicator {
         Ok(())
     }
 
+    pub async fn present_walkthrough(&self, walkthrough: crate::ide::ResolvedWalkthrough) -> Result<()> {
+        if self.test_mode {
+            info!("Present walkthrough called (test mode): {:?}", walkthrough);
+            return Ok(());
+        }
+
+        let payload = serde_json::to_value(&walkthrough)?;
+
+        let shell_pid = {
+            let inner = self.inner.lock().await;
+            inner.terminal_shell_pid
+        };
+        
+        let message = IPCMessage {
+            shell_pid,
+            message_type: IPCMessageType::PresentWalkthrough,
+            payload,
+            id: Uuid::new_v4().to_string(),
+        };
+
+        debug!("Sending present_walkthrough message: {:?}", message);
+        trace!("About to call send_message_with_reply for present_walkthrough");
+
+        let response: () = self.send_message_with_reply(message).await?;
+
+        trace!(
+            "Received response from send_message_with_reply: {:?}",
+            response
+        );
+        info!("Successfully presented walkthrough to VSCode");
+
+        Ok(())
+    }
+
     pub async fn get_selection(&self) -> Result<GetSelectionResult> {
         if self.test_mode {
             info!("Get selection called (test mode)");

server/src/server.rs

@@ -282,20 +282,25 @@ impl DialecticServer {
             highlights: self.process_walkthrough_elements(params.highlights.as_ref()).await?,
             changes: self.process_walkthrough_elements(params.changes.as_ref()).await?,
             actions: self.process_walkthrough_elements(params.actions.as_ref()).await?,
+            base_uri: params.base_uri.clone(),
         };
 
-        // Log the processing result
+        // Send resolved walkthrough to VSCode extension
+        self.ipc
+            .present_walkthrough(resolved)
+            .await
+            .map_err(|e| McpError::internal_error("Failed to present walkthrough", Some(serde_json::json!({"error": e.to_string()}))))?;
+        
+        // Log success
         self.ipc
             .send_log(
                 LogLevel::Info,
-                format!("Processed walkthrough with {} sections", 
-                    [&resolved.introduction, &resolved.highlights, &resolved.changes, &resolved.actions]
-                        .iter().filter(|s| s.is_some()).count()),
+                "Walkthrough successfully sent to VSCode".to_string(),
             )
             .await;
 
         Ok(CallToolResult::success(vec![Content::text(
-            "Walkthrough successfully processed",
+            "Walkthrough successfully processed and presented in VSCode",
         )]))
     }