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/memory/mmap_windows.go

@@ -0,0 +1,58 @@
+// Copyright 2017 The Memory 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 memory // import "modernc.org/memory"
+
+import (
+	syscall "golang.org/x/sys/windows"
+	"os"
+)
+
+const (
+	_MEM_COMMIT   = 0x1000
+	_MEM_RESERVE  = 0x2000
+	_MEM_DECOMMIT = 0x4000
+	_MEM_RELEASE  = 0x8000
+
+	_PAGE_READWRITE = 0x0004
+	_PAGE_NOACCESS  = 0x0001
+)
+
+const pageSizeLog = 16
+
+// canCarve is false on Windows: VirtualFree with MEM_RELEASE frees
+// only whole VirtualAlloc allocations, never a sub-range.
+const canCarve = false
+
+// mmapGranularity is the granularity mmap in this file actually maps at:
+// VirtualAlloc reserves at 64 KiB granularity, so mmap rounds every request
+// up to a pageSize multiple and page.size records that.
+const mmapGranularity = pageSize
+
+var (
+	modkernel32      = syscall.NewLazySystemDLL("kernel32.dll")
+	osPageMask       = osPageSize - 1
+	osPageSize       = os.Getpagesize()
+	procVirtualAlloc = modkernel32.NewProc("VirtualAlloc")
+	procVirtualFree  = modkernel32.NewProc("VirtualFree")
+)
+
+// pageSize aligned.
+func mmap(size int) (uintptr, int, error) {
+	size = roundup(size, pageSize)
+	addr, _, err := procVirtualAlloc.Call(0, uintptr(size), _MEM_COMMIT|_MEM_RESERVE, _PAGE_READWRITE)
+	if err.(syscall.Errno) != 0 || addr == 0 {
+		return addr, size, err
+	}
+	return addr, size, nil
+}
+
+func unmap(addr uintptr, size int) error {
+	r, _, err := procVirtualFree.Call(addr, 0, _MEM_RELEASE)
+	if r == 0 {
+		return err
+	}
+
+	return nil
+}