🤖 feat: copy plan file when forking workspace

When a workspace is forked via /fork, the plan file is now copied
along with the chat history, partial state, and usage tracking.

This allows the forked workspace to continue working with the same
plan context as the original.

Changes:
- Add copyPlanFile helper in src/node/utils/runtime/helpers.ts
- Call copyPlanFile in workspaceService.fork() after session files

Change-Id: Iaee04cb44c1b5a98e13eb693fa729a078b8d0013
Signed-off-by: Thomas Kosiewski <[email protected]>

Author: ThomasK33

src/node/services/workspaceService.ts

@@ -56,7 +56,7 @@ import { createBashTool } from "@/node/services/tools/bash";
 import type { AskUserQuestionToolSuccessResult, BashToolResult } from "@/common/types/tools";
 import { secretsToRecord } from "@/common/types/secrets";
 
-import { movePlanFile } from "@/node/utils/runtime/helpers";
+import { movePlanFile, copyPlanFile } from "@/node/utils/runtime/helpers";
 
 /** Maximum number of retry attempts when workspace name collides */
 const MAX_WORKSPACE_NAME_COLLISION_RETRIES = 3;
@@ -960,6 +960,9 @@ export class WorkspaceService extends EventEmitter {
         return Err(`Failed to copy chat history: ${message}`);
       }
 
+      // Copy plan file if it exists (checks both new and legacy paths)
+      await copyPlanFile(runtime, sourceMetadata.name, sourceWorkspaceId, newName, projectName);
+
       // Compute namedWorkspacePath for frontend metadata
       const namedWorkspacePath = runtime.getWorkspacePath(foundProjectPath, newName);
 

src/node/utils/runtime/helpers.ts

@@ -190,8 +190,47 @@ export async function movePlanFile(
 
   try {
     await runtime.stat(oldPath);
-    await execBuffered(runtime, `mv "${oldPath}" "${newPath}"`, { cwd: "/tmp", timeout: 5 });
+    // Resolve tildes to absolute paths - bash doesn't expand ~ inside quotes
+    const resolvedOldPath = await runtime.resolvePath(oldPath);
+    const resolvedNewPath = await runtime.resolvePath(newPath);
+    await execBuffered(runtime, `mv "${resolvedOldPath}" "${resolvedNewPath}"`, {
+      cwd: "/tmp",
+      timeout: 5,
+    });
   } catch {
     // No plan file to move, that's fine
   }
 }
+
+/**
+ * Copy a plan file from one workspace to another (e.g., during fork).
+ * Checks both new path format and legacy path format for the source.
+ * Silently succeeds if source file doesn't exist at either location.
+ */
+export async function copyPlanFile(
+  runtime: Runtime,
+  sourceWorkspaceName: string,
+  sourceWorkspaceId: string,
+  targetWorkspaceName: string,
+  projectName: string
+): Promise<void> {
+  const sourcePath = getPlanFilePath(sourceWorkspaceName, projectName);
+  const legacySourcePath = getLegacyPlanFilePath(sourceWorkspaceId);
+  const targetPath = getPlanFilePath(targetWorkspaceName, projectName);
+
+  // Prefer the new layout, but fall back to the legacy layout.
+  //
+  // Note: we intentionally use runtime file I/O instead of `cp` because:
+  // 1) bash doesn't expand ~ inside quotes
+  // 2) the target per-project plan directory may not exist yet
+  // 3) runtime.writeFile() already handles directory creation + tilde expansion
+  for (const candidatePath of [sourcePath, legacySourcePath]) {
+    try {
+      const content = await readFileString(runtime, candidatePath);
+      await writeFileString(runtime, targetPath, content);
+      return;
+    } catch {
+      // Try next candidate
+    }
+  }
+}