Remove abort signal handling from LocalRuntime operations

Local file operations (readFile, writeFile, stat, renameWorkspace, deleteWorkspace)
are fast and don't need cancellation support. The abort signal parameters remain
in the interface for SSHRuntime, but LocalRuntime now ignores them with a comment
explaining why.

This simplifies LocalRuntime while keeping abort signal support where it matters
most - in SSHRuntime's network-bound operations.

Author: ammar-agent

src/runtime/LocalRuntime.ts

@@ -210,27 +210,14 @@ export class LocalRuntime implements Runtime {
   }
 
   readFile(filePath: string, abortSignal?: AbortSignal): ReadableStream<Uint8Array> {
+    // Note: abortSignal ignored for local operations (fast, no need for cancellation)
     const nodeStream = fs.createReadStream(filePath);
 
     // Handle errors by wrapping in a transform
     const webStream = Readable.toWeb(nodeStream) as unknown as ReadableStream<Uint8Array>;
 
     return new ReadableStream<Uint8Array>({
       async start(controller: ReadableStreamDefaultController<Uint8Array>) {
-        // Check if already aborted
-        if (abortSignal?.aborted) {
-          controller.error(new Error("Read operation aborted"));
-          nodeStream.destroy();
-          return;
-        }
-
-        // Set up abort listener
-        const abortHandler = () => {
-          controller.error(new Error("Read operation aborted"));
-          nodeStream.destroy();
-        };
-        abortSignal?.addEventListener("abort", abortHandler);
-
         try {
           const reader = webStream.getReader();
           while (true) {
@@ -247,24 +234,18 @@ export class LocalRuntime implements Runtime {
               err instanceof Error ? err : undefined
             )
           );
-        } finally {
-          abortSignal?.removeEventListener("abort", abortHandler);
         }
       },
     });
   }
 
   writeFile(filePath: string, abortSignal?: AbortSignal): WritableStream<Uint8Array> {
+    // Note: abortSignal ignored for local operations (fast, no need for cancellation)
     let tempPath: string;
     let writer: WritableStreamDefaultWriter<Uint8Array>;
 
     return new WritableStream<Uint8Array>({
       async start() {
-        // Check if already aborted
-        if (abortSignal?.aborted) {
-          throw new Error("Write operation aborted");
-        }
-
         // Create parent directories if they don't exist
         const parentDir = path.dirname(filePath);
         await fsPromises.mkdir(parentDir, { recursive: true });
@@ -274,19 +255,8 @@ export class LocalRuntime implements Runtime {
         const nodeStream = fs.createWriteStream(tempPath);
         const webStream = Writable.toWeb(nodeStream) as WritableStream<Uint8Array>;
         writer = webStream.getWriter();
-
-        // Set up abort listener
-        const abortHandler = () => {
-          writer.abort("Write operation aborted").catch(() => {
-            // Ignore errors during abort
-          });
-        };
-        abortSignal?.addEventListener("abort", abortHandler);
       },
       async write(chunk: Uint8Array) {
-        if (abortSignal?.aborted) {
-          throw new Error("Write operation aborted");
-        }
         await writer.write(chunk);
       },
       async close() {
@@ -319,11 +289,7 @@ export class LocalRuntime implements Runtime {
   }
 
   async stat(filePath: string, abortSignal?: AbortSignal): Promise<FileStat> {
-    // Check if already aborted
-    if (abortSignal?.aborted) {
-      throw new Error("Stat operation aborted");
-    }
-
+    // Note: abortSignal ignored for local operations (fast, no need for cancellation)
     try {
       const stats = await fsPromises.stat(filePath);
       return {
@@ -504,10 +470,7 @@ export class LocalRuntime implements Runtime {
   ): Promise<
     { success: true; oldPath: string; newPath: string } | { success: false; error: string }
   > {
-    // Check if already aborted
-    if (abortSignal?.aborted) {
-      return { success: false, error: "Rename operation aborted" };
-    }
+    // Note: abortSignal ignored for local operations (fast, no need for cancellation)
     // Compute workspace paths using canonical method
     const oldPath = this.getWorkspacePath(projectPath, oldName);
     const newPath = this.getWorkspacePath(projectPath, newName);
@@ -530,11 +493,7 @@ export class LocalRuntime implements Runtime {
     force: boolean,
     abortSignal?: AbortSignal
   ): Promise<{ success: true; deletedPath: string } | { success: false; error: string }> {
-    // Check if already aborted
-    if (abortSignal?.aborted) {
-      return { success: false, error: "Delete operation aborted" };
-    }
-
+    // Note: abortSignal ignored for local operations (fast, no need for cancellation)
     // Compute workspace path using the canonical method
     const deletedPath = this.getWorkspacePath(projectPath, workspaceName);