M1 progress: engine port compiles except pf.c; AF_DIVERT socket family; ifq framework

- compat layer extended through the full BSD API surface pf_ioctl/pf_lb/
  pf_if/pf_norm/pf_table/pf_ruleset/radix/md5/sha2 need (all compile):
  cpumem/counters model, ifaddr/ifg groups, cred view, endian+in6 names,
  NAT46/64, SipHash24, mbuf_list, frag6 helpers, ip6 forward/checksum,
  tcp options/FSM names, taskqueue & sysctl shims (documented in
  docs/porting-notes.md)
- pfsrc/divert_sock.c: real BSD divert(4) as runtime-registered PF_DIVERT=32
  socket family inside the module (sock_register; NPROTO=AF_MAX=45 -> zero
  core patches); divert_packet/divert6_packet wired for pf.c
- compat/pfk_ifq.c: OpenBSD 8.0 ifq framework with priq back end; hfsc and
  fq_codel aliases pending M5 (recorded in feature matrix as pending)
- design + plan updated for the divert decision (user-requested)
- stage-port.sh: single deterministic rename program for headers and .c

module/Makefile

@@ -1,17 +1,27 @@
 # PF-on-Linux kernel module build (out-of-tree)
 # Build:  make -C /path/to/linux-7.3.4 M=$PWD   (or scripts/build-module.sh)
+#
+# -D_KERNEL=1 selects the kernel-side branches of the staged OpenBSD sources
+# (the same files also contain userland-only code guarded by #ifndef _KERNEL).
 ccflags-y := -I$(src)/include -I$(src)/include/compat -DPFLINUX=1 \
-             -Wno-declaration-after-statement
+             -D_KERNEL=1 \
+             -Wno-declaration-after-statement \
+             -Wno-implicit-fallthrough \
+             -Wno-frame-larger-than
 
-# M1 skeleton set — staged engine files (pf.c, pf_ioctl.c, ...) are added
-# per plan tasks T7b/T10/T11/T12; keep list explicit (no wildcards).
+# our glue + compat layer
 pf-objs := pfsrc/pfk_mod.o pfsrc/pfk_hooks.o \
            compat/pfk_mbuf.o compat/pfk_kern.o compat/pfk_if.o compat/pfk_xmit.o \
-           compat/siphash.o compat/toeplitz.o compat/md5.o compat/sha2.o
-# staged BSD sources (uncomment as ported):
-# pf-objs += compat/sha2.o compat/sha1.o compat/siphash.o compat/toeplitz.o
-# pf-objs += compat/radix.o compat/rtable.o
-# pf-objs += pfsrc/pf.o pfsrc/pf_ioctl.o pfsrc/pf_norm.o pfsrc/pf_if.o pfsrc/pf_lb.o
-# pf-objs += pfsrc/pf_ruleset.o pfsrc/pf_table.o pfsrc/pf_osfp.o pfsrc/pf_syncookies.o
+           compat/siphash.o compat/toeplitz.o compat/md5.o compat/sha2.o \
+           compat/radix.o compat/pfk_rtable.o compat/pfk_ip6.o
+
+# ported OpenBSD 8.0 engine
+pf-objs += pfsrc/pf_ruleset.o pfsrc/pf_table.o pfsrc/pf_norm.o pfsrc/pf_if.o \
+           pfsrc/pf_lb.o pfsrc/pf_osfp.o pfsrc/pf_syncookies.o \
+           pfsrc/pf_ioctl.o pfsrc/pf.o pfsrc/divert_sock.o
+
+# queueing framework (compat/pfk_ifq.c implements the ifq API with priq
+# semantics; the OpenBSD hfsc/fq_codel back ends land in milestone M5)
+pf-objs += compat/pfk_ifq.o
 
 obj-m := pf.o