Fix unguarded vlt lockfile reads to prevent FIFO hangs

Replace bare tokio::fs::read_to_string and tokio::fs::read calls with
guarded read_regular_to_string and read_regular_to_bytes from
socket_patch_core::utils::fs. These guarded readers use O_NONBLOCK
and verify files are regular before reading, preventing indefinite
hangs when a FIFO or device is placed at the lockfile path.

Fixes:
- rollback.rs: vlt-lock.json read during hosted rollback
- repair_vendor.rs: vlt-lock.json and package.json reads during repair

Author: cursoragent

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

@@ -56,7 +56,7 @@ use socket_patch_core::constants::SOCKET_DIR;
 use socket_patch_core::crawlers::CrawlerOptions;
 use socket_patch_core::manifest::schema::{PatchManifest, PatchRecord};
 use socket_patch_core::patch::copy_tree::remove_tree;
-use socket_patch_core::utils::fs::read_regular_to_string;
+use socket_patch_core::utils::fs::{read_regular_to_bytes, read_regular_to_string};
 use socket_patch_core::utils::purl::{
     normalize_purl, percent_decode_purl_component, strip_purl_qualifiers,
 };
@@ -1546,7 +1546,7 @@ pub(crate) async fn repair_vendored_artifacts_with_references(
                 names.extend(vendor::vlt_lock::vlt_importer_package_jsons(&common.cwd).await);
                 for name in names {
                     let p = common.cwd.join(name);
-                    if let Ok(bytes) = tokio::fs::read(&p).await {
+                    if let Ok(bytes) = read_regular_to_bytes(&p).await {
                         snap.push((p, Some(bytes)));
                     }
                 }

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

@@ -15,6 +15,7 @@ use socket_patch_core::patch::rollback::{
     VerifyRollbackResult, VerifyRollbackStatus,
 };
 use socket_patch_core::telemetry::{track_patch_rollback_failed, track_patch_rolled_back};
+use socket_patch_core::utils::fs::read_regular_to_string;
 use socket_patch_core::utils::purl::{patch_matches, strip_purl_qualifiers};
 use socket_patch_core::vendor::{save_state, RevertOpts, VendorState, VendorWarning};
 use std::collections::{HashMap, HashSet};
@@ -1054,8 +1055,8 @@ pub(crate) async fn run_hosted_leg(
     } else {
         purls.to_vec()
     };
-    let vlt_lock = tokio::fs::read_to_string(
-        common
+    let vlt_lock = read_regular_to_string(
+        &common
             .cwd
             .join(socket_patch_core::constants::npm_family::VLT_LOCK),
     )