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/modernc.org/libc/libc_musl_linux_arm.go

@@ -0,0 +1,75 @@
+// Copyright 2023 The Libc Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package libc // import "modernc.org/libc"
+
+import (
+	"math/bits"
+	"sync/atomic"
+	"unsafe"
+)
+
+type long = int32
+
+type ulong = uint32
+
+var (
+	___a_barrier_ptr ulong
+)
+
+// RawMem represents the biggest byte array the runtime can handle
+type RawMem [1<<31 - 1]byte
+
+// void *memcpy(void *dest, const void *src, size_t n);
+//
+// musl implements memcpy in assembly on arm, so ccgo never transpiled one
+// and this hand-written version used to be Xmemcpy. Xmemcpy now lives in
+// native_musl.go; this stays under the ___musl_ name generator.go gives
+// the transpiled originals, for native_musl_test.go.
+func ___musl_memcpy(t *TLS, dest, src uintptr, n Tsize_t) (r uintptr) {
+	if __ccgo_strace {
+		trc("t=%v src=%v n=%v, (%v:)", t, src, n, origin(2))
+		defer func() { trc("-> %v", r) }()
+	}
+	return _memcpy(t, dest, src, n)
+}
+
+func _memcpy(t *TLS, dest, src uintptr, n Tsize_t) (r uintptr) {
+	if n != 0 {
+		copy((*RawMem)(unsafe.Pointer(dest))[:n:n], (*RawMem)(unsafe.Pointer(src))[:n:n])
+	}
+	return dest
+}
+
+func _fetestexcept(t *TLS, _ int32) int32 {
+	return 0
+}
+
+func _feclearexcept(t *TLS, _ int32) int32 {
+	return 0
+}
+
+func _a_crash(tls *TLS) {
+	panic("crash")
+}
+
+var atomicBarrier atomic.Int32
+
+func _a_barrier(tls *TLS) {
+	atomicBarrier.Add(1)
+}
+
+// static inline int a_sc(volatile int *p, int v)
+func _a_sc(*TLS, uintptr, int32) int32 {
+	panic(todo(""))
+}
+
+// static inline int a_ll(volatile int *p)
+func _a_ll(tls *TLS, p uintptr) int32 {
+	return atomic.LoadInt32((*int32)(unsafe.Pointer(p)))
+}
+
+func _a_clz_32(tls *TLS, x uint32) int32 {
+	return int32(bits.LeadingZeros32(x))
+}