Retire a pre-v5 hosted ledger when rollback finds nothing else; update the cargo guard test

rollback in a project whose only state is a stale pre-v5
redirect-state.json (no manifest, no vendor ledger, no hosted pin in the
lockfiles) removes that file and exits 0 instead of failing on the missing
manifest.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018tncU7u7FK48tubFNA12UQ

Author: claude

crates/socket-patch-cli/src/commands/rollback.rs

@@ -1210,6 +1210,42 @@ pub async fn run(args: RollbackArgs) -> i32 {
         HostedPin::all(&crate::commands::discover_wiring(&args.common, &cwd).await);
 
     if manifest_missing && !vendor_ledger_exists && hosted_pins.is_empty() {
+        // Only a pre-v5 hosted ledger left: no lockfile pins it any more,
+        // so there is nothing to restore — retire the stale file (a wet run
+        // only) instead of failing on the missing manifest.
+        let legacy = cwd.join(socket_patch_core::patch::redirect::REDIRECT_STATE_REL);
+        if tokio::fs::symlink_metadata(&legacy).await.is_ok() {
+            let warning = retire_legacy_redirect_ledger(&args.common).await;
+            if args.common.json {
+                println!(
+                    "{}",
+                    serde_json::to_string_pretty(&serde_json::json!({
+                        "status": "success",
+                        "rolledBack": 0,
+                        "alreadyOriginal": 0,
+                        "failed": 0,
+                        "dryRun": args.common.dry_run,
+                        "warnings": warning
+                            .iter()
+                            .map(|(code, detail)| serde_json::json!({
+                                "code": code, "detail": detail,
+                            }))
+                            .collect::<Vec<_>>(),
+                        "legacyRedirectLedgerRemoved": warning.is_none() && !args.common.dry_run,
+                    }))
+                    .expect("serializing an in-memory JSON value cannot fail")
+                );
+            } else if let Some((code, detail)) = &warning {
+                eprintln!("Warning ({code}): {}", capitalize_first(detail));
+            } else if !args.common.silent {
+                println!(
+                    "{} the pre-v5 hosted ledger {}: no lockfile pins a hosted patch.",
+                    if args.common.dry_run { "Would remove" } else { "Removed" },
+                    socket_patch_core::patch::redirect::REDIRECT_STATE_REL
+                );
+            }
+            return 0;
+        }
         // Ledger-less but still wired? (a deleted/uncommitted state.json
         // with lockfiles still consuming `.socket/vendor/` artifacts is a
         // supported recovery state — `repair` reconstructs the ledger.)

crates/socket-patch-core/src/vendor/cargo.rs

@@ -4201,12 +4201,12 @@ mod tests {
         );
     }
 
-    /// FAIL CLOSED: vendoring over a LIVE hosted redirect with no ledger to
-    /// revert it must refuse — proceeding would record the hosted registry
+    /// FAIL CLOSED: vendoring over a LIVE hosted redirect the upstream
+    /// restore did not undo must refuse — proceeding would record the hosted registry
     /// values as the entry's "originals" and leave Cargo.toml pinned to the
     /// hosted registry (unbuildable in both modes) while reporting success.
     #[tokio::test]
-    async fn test_refuses_live_hosted_redirect_without_ledger() {
+    async fn test_refuses_live_hosted_redirect_left_unrestored() {
         let (dir, blobs, pristine, record) = fixture().await;
         let root = dir.path();
         let index = "sparse+http://127.0.0.1:5555/index/";
@@ -4243,7 +4243,12 @@ mod tests {
             run_vendor(PURL, root, &blobs, &pristine, &record, false).await,
             "hosted_redirect_live",
         );
-        assert!(detail.contains("redirect-state.json"), "{detail}");
+        assert!(
+            detail.contains("socket-patch rollback")
+                && detail.contains("git checkout -- Cargo.toml Cargo.lock"),
+            "the refusal names the restore remedies: {detail}"
+        );
+        assert!(!detail.contains("redirect-state.json"), "{detail}");
         // Nothing was half-vendored.
         assert!(!root.join(format!(".socket/vendor/cargo/{UUID}")).exists());