bootstrap: fix redox-scheme API skew (IntoTag path + ref-in-pattern)

base-initfs 'bootstrap' bin failed to compile against current redox-scheme:
- IntoTag is re-exported only from redox_scheme::scheme (top-level path is
  private) -> import it from scheme::{...} (fixes E0603 + the E0599 into_tag
  not-in-scope at initnsmgr.rs:242).
- Op::OpenAt(ref o) uses an explicit 'ref' inside matches!(&op, ...) which is
  now rejected under match ergonomics ('cannot explicitly borrow within an
  implicitly-borrowing pattern') -> drop 'ref'.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

bootstrap/src/initnsmgr.rs

@@ -18,9 +18,9 @@ use redox_rt::proc::FdGuard;
 // local/docs/legacy-obsolete-2026-07-25/INITNSMGR-CONCURRENCY-DESIGN.md.
 use redox_rt::sync::Mutex;
 use redox_scheme::{
-    CallerCtx, Id, IntoTag, OpenResult, RequestKind, Response, SendFdRequest, SignalBehavior,
+    CallerCtx, Id, OpenResult, RequestKind, Response, SendFdRequest, SignalBehavior,
     Socket, Tag,
-    scheme::{Op, OpFdPathLike, SchemeState, SchemeSync},
+    scheme::{IntoTag, Op, OpFdPathLike, SchemeState, SchemeSync},
 };
 use syscall::Stat;
 use syscall::dirent::{DirEntry, DirentBuf, DirentKind};
@@ -688,7 +688,7 @@ pub fn run(
                     Ok(op) => {
                         let intercept = matches!(
                             &op,
-                            Op::OpenAt(ref o) if is_scheme_forwarded(o.path())
+                            Op::OpenAt(o) if is_scheme_forwarded(o.path())
                         );
                         if intercept {
                             match op {