fix(server): name the missing file instead of a generic read failure

apps/server/src/server.test.ts

@@ -4943,6 +4943,69 @@ it.layer(NodeServices.layer)("server router seam", (it) => {
     }).pipe(Effect.provide(NodeHttpServer.layerTest)),
   );
 
+  it.effect("names a missing workspace file instead of reporting a generic read failure", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const workspaceDir = yield* fs.makeTempDirectoryScoped({
+        prefix: "t3-ws-workspace-missing-file-",
+      });
+
+      yield* buildAppUnderTest();
+
+      const wsUrl = yield* getWsServerUrl("/ws");
+      const result = yield* Effect.scoped(
+        withWsRpcClient(wsUrl, (client) =>
+          client[WS_METHODS.projectsReadFile]({
+            cwd: workspaceDir,
+            relativePath: "components/selectors/Missing.vue",
+          }).pipe(Effect.result),
+        ),
+      );
+
+      if (result._tag !== "Failure" || result.failure._tag !== "ProjectReadFileError") {
+        assert.fail("Expected a ProjectReadFileError");
+      }
+      const readError = result.failure;
+      assert.equal(
+        readError.message,
+        `Workspace file 'components/selectors/Missing.vue' does not exist in '${workspaceDir}'.`,
+      );
+      assert.equal(readError.cwd, workspaceDir);
+      assert.equal(readError.relativePath, "components/selectors/Missing.vue");
+      assert.equal(readError.failure, "file_not_found");
+      assert.isDefined(readError.cause);
+    }).pipe(Effect.provide(NodeHttpServer.layerTest)),
+  );
+
+  it.effect("does not blame the file when the workspace root itself is missing", () =>
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem;
+      const path = yield* Path.Path;
+      const parentDir = yield* fs.makeTempDirectoryScoped({
+        prefix: "t3-ws-workspace-missing-root-",
+      });
+      const missingWorkspace = path.join(parentDir, "gone");
+
+      yield* buildAppUnderTest();
+
+      const wsUrl = yield* getWsServerUrl("/ws");
+      const result = yield* Effect.scoped(
+        withWsRpcClient(wsUrl, (client) =>
+          client[WS_METHODS.projectsReadFile]({
+            cwd: missingWorkspace,
+            relativePath: "anything.txt",
+          }).pipe(Effect.result),
+        ),
+      );
+
+      if (result._tag !== "Failure" || result.failure._tag !== "ProjectReadFileError") {
+        assert.fail("Expected a ProjectReadFileError");
+      }
+      assert.equal(result.failure.failure, "operation_failed");
+      assert.notInclude(result.failure.message, "does not exist in");
+    }).pipe(Effect.provide(NodeHttpServer.layerTest)),
+  );
+
   it.effect("reports workspace root stat failures without relabeling them as missing", () =>
     Effect.gen(function* () {
       if ((yield* HostProcessPlatform) === "win32") return;

apps/server/src/ws.ts

@@ -238,7 +238,14 @@ function projectFileFailureContext(
       return { failure: "workspace_path_outside_root" };
     case "WorkspaceFileSystemOperationError":
       return {
-        failure: "operation_failed",
+        // Only ENOENT means the target is genuinely absent, and a missing
+        // workspace root raises it through the same operation, so neither a
+        // permission error nor a missing root is reported as a missing file.
+        failure:
+          error.operation !== "realpath-workspace-root" &&
+          (error.cause as { readonly code?: unknown } | undefined)?.code === "ENOENT"
+            ? "file_not_found"
+            : "operation_failed",
         resolvedPath: error.resolvedPath,
         operation: error.operation,
         operationPath: error.operationPath,

packages/contracts/src/project.ts

@@ -209,6 +209,7 @@ export const ProjectFileFailure = Schema.Literals([
   "workspace_path_outside_root",
   "resolved_path_outside_root",
   "path_not_file",
+  "file_not_found",
   "binary_file",
   "operation_failed",
 ]);
@@ -257,7 +258,9 @@ export class ProjectReadFileError extends Schema.TaggedErrorClass<ProjectReadFil
       ...props,
       message:
         decodedProjectErrorMessage(props) ??
-        `Failed to read workspace file '${props.relativePath}' in '${props.cwd}'.`,
+        (props.failure === "file_not_found"
+          ? `Workspace file '${props.relativePath}' does not exist in '${props.cwd}'.`
+          : `Failed to read workspace file '${props.relativePath}' in '${props.cwd}'.`),
     } as any);
   }
 }