p2: digest with in-sift FIFO, SQLite caches, Honcho context, recover

Dixie is capped (max_inflight 2, queue_depth 8, queue_wait 20s) and
never queued on llama-server. Streaming chat, thinking off, 45s
fallback to clean. Digest and chunk-embedding caches are
content-addressed SQLite (Honcho context is not cached). Recover
uses the guarded Fetcher. guardian-star is refused in code.

vendor/golang.org/x/sys/unix/syscall_hurd.go

@@ -0,0 +1,30 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build hurd
+
+package unix
+
+/*
+#include <stdint.h>
+int ioctl(int, unsigned long int, uintptr_t);
+*/
+import "C"
+import "unsafe"
+
+func ioctl(fd int, req uint, arg uintptr) (err error) {
+	r0, er := C.ioctl(C.int(fd), C.ulong(req), C.uintptr_t(arg))
+	if r0 == -1 && er != nil {
+		err = er
+	}
+	return
+}
+
+func ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) {
+	r0, er := C.ioctl(C.int(fd), C.ulong(req), C.uintptr_t(uintptr(arg)))
+	if r0 == -1 && er != nil {
+		err = er
+	}
+	return
+}