feat(errors): add caller-safe typed error projections

src/application/ProcessCaptureError.ts

@@ -1,6 +1,30 @@
 import { AnalysisError } from "../domain/errors.js";
 
+interface ProcessCaptureErrorOptions extends ErrorOptions {
+  readonly userMessage?: string;
+  readonly userCategory?: "permission_required" | "cancelled";
+}
+
 /** Typed application failure produced by controlled process capture. */
 export class ProcessCaptureError extends AnalysisError {
   readonly _tag = "ProcessCaptureError";
+
+  override readonly userMessage: string | undefined;
+  override readonly userCategory:
+    | "permission_required"
+    | "cancelled"
+    | undefined;
+
+  constructor(message: string, options?: ProcessCaptureErrorOptions) {
+    super(message, options);
+    this.userMessage = options?.userMessage;
+    this.userCategory = options?.userCategory;
+  }
 }
+
+/** Caller-visible cancellation without exposing capture implementation state. */
+export const processCaptureCancelled = (): ProcessCaptureError =>
+  new ProcessCaptureError("process capture was cancelled", {
+    userCategory: "cancelled",
+    userMessage: "Process capture was cancelled. Start it again when ready.",
+  });