refactor: split remote gc runner and degraded helpers

scripts/src/gc-remote-degraded.ts

@@ -0,0 +1,38 @@
+import { classifySshTcpPoolFailure, type SshCaptureResult } from "./ssh";
+
+export function remoteGcDegradedFailure(providerId: string, action: string, result: SshCaptureResult): Record<string, unknown> {
+  const text = `${result.stderr}\n${result.stdout}`;
+  const failureKind = classifySshTcpPoolFailure(text);
+  const timeout = result.exitCode === 124 || text.includes("ssh-runtime-timeout");
+  const providerOffline = text.includes(`provider is not online: ${providerId}`) || text.includes("provider is not online");
+  const degradedReason = failureKind ?? (providerOffline ? "provider-offline" : timeout ? "ssh-runtime-timeout" : "remote-command-failed");
+  return {
+    ok: false,
+    degraded: true,
+    providerId,
+    action: `gc remote ${action}`,
+    degradedReason,
+    transport: {
+      sshTcpPoolFailureKind: failureKind,
+      providerOffline,
+      sshRuntimeTimeout: timeout,
+      exitCode: result.exitCode,
+    },
+    safeCandidateCount: null,
+    runAllowed: false,
+    mutation: false,
+    summary: failureKind !== null
+      ? `remote GC could not acquire a provider data channel: ${failureKind}`
+      : providerOffline
+        ? `provider ${providerId} is offline from the controlled CLI transport view`
+        : timeout
+          ? "remote GC did not complete before the SSH runtime timeout"
+          : "remote GC command failed before producing a valid plan",
+    next: {
+      sshPool: `bun scripts/cli.ts debug ssh-pool ${providerId}`,
+      fullHealth: "bun scripts/cli.ts debug health",
+      smoke: `trans ${providerId} argv true`,
+      retryPlan: `bun scripts/cli.ts gc remote ${providerId} plan --no-snapshot-save`,
+    },
+  };
+}