fix(ghidra): preserve lifecycle ownership and failure provenance

Refs #4502, #4506, #4508, #4518, #4522, #4526.

Retain snapshot, endpoint, launch rollback and compiler cleanup owners. Join request finalization and cleanup cancellation. Preserve bounded compiler output and original byte counts through capture and Ghidra failures. Normalize execFile cancellation once at its producer.

Validation includes real macOS Ghidra TCP MCP success workflows, controlled Node compiler/process fault fixtures, focused regressions and static checks. Native Swift compiler faults, Windows execution and stdio transport were not verified. Broader startup primary classification in #4517 and native adapter propagation remain unfinished.

src/process/ExecFileOutput.ts

@@ -21,14 +21,16 @@ type ExecFileOutputOptions = Omit<
 /** How long a stopped process may take to exit before it is killed. */
 const STOP_GRACE_MS = 5_000;
 
-const abortError = (signal: AbortSignal): Error => {
-  const error = new Error("The operation was aborted", {
-    cause: signal.reason,
-  });
-  error.name = "AbortError";
-  Reflect.set(error, "code", "ABORT_ERR");
-  return error;
-};
+/** Cancellation observed by the command owner, with the caller's exact reason. */
+export class ExecFileOutputCancelledError extends Error {
+  readonly _tag = "ExecFileOutputCancelledError";
+  readonly code = "ABORT_ERR";
+
+  constructor(reason: unknown) {
+    super("The operation was aborted", { cause: reason });
+    this.name = "AbortError";
+  }
+}
 
 /**
  * A command stopped at its timeout can still exit cleanly, so the timeout is
@@ -133,7 +135,7 @@ export const execFileBytes = (
       return;
     }
     if (stopSignal !== undefined && signal?.aborted === true) {
-      reject(abortError(signal));
+      reject(new ExecFileOutputCancelledError(signal.reason));
       return;
     }
     let stopped: "abort" | "timeout" | undefined;
@@ -162,10 +164,12 @@ export const execFileBytes = (
         clearTimeout(grace);
         const failure =
           stopped === "abort" && signal !== undefined
-            ? abortError(signal)
+            ? new ExecFileOutputCancelledError(signal.reason)
             : stopped === "timeout" && timeout !== undefined
               ? timeoutError(command, timeout, error)
-              : error;
+              : error?.name === "AbortError" && error.code === "ABORT_ERR"
+                ? new ExecFileOutputCancelledError(error.cause)
+                : error;
         if (failure !== null) {
           Reflect.set(failure, "stdout", stdout.toString("utf8"));
           Reflect.set(failure, "stderr", stderr.toString("utf8"));