fix(javascript): preserve recovery acquisition and cancellation failures

src/application/javascript/JavaScriptRecoveryService.test.ts

@@ -123,11 +123,14 @@ describe("JavaScript recovery workflow", () => {
     const invalid = await service.recover({});
     if (invalid.ok) throw new Error("expected malformed input");
     expect(invalid.error._tag).toBe("AnalysisInputError");
-    const cancelled = await service.recover(input, {
-      signal: AbortSignal.abort(),
-    });
-    if (cancelled.ok) throw new Error("expected cancellation");
-    expect(cancelled.error._tag).toBe("AnalysisCancelledError");
+    for (const reason of [null, false, { request: "cancel recovery" }]) {
+      const cancelled = await service.recover(input, {
+        signal: AbortSignal.abort(reason),
+      });
+      if (cancelled.ok) throw new Error("expected cancellation");
+      expect(cancelled.error._tag).toBe("AnalysisCancelledError");
+      expect(cancelled.error.cause).toBe(reason);
+    }
   });
   it("rejects additional_paths repeating path or each other", async () => {
     const service = new JavaScriptRecoveryService({

src/application/javascript/JavaScriptRecoveryService.ts

@@ -34,7 +34,9 @@ export class JavaScriptRecoveryService {
     options?: ExecutionOptions,
   ): Promise<Result<Evidence, AnalysisError>> {
     if (options?.signal?.aborted === true)
-      return err(new AnalysisCancelledError(OPERATION));
+      return err(
+        new AnalysisCancelledError(OPERATION, { cause: options.signal.reason }),
+      );
     const parsed = javascriptRecoveryInputSchema.safeParse(input);
     if (!parsed.success)
       return err(