Debian: split DKMS into separate binary package

The package deps seems to be correct,
and the mod does seem to get built
and placed into initramfs.

```
$ eatmydata sudo dpkg -i bcachefs-tools_1.31.3_amd64.deb
ERROR: ld.so: object 'libeatmydata.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
(Reading database ... 534575 files and directories currently installed.)
Preparing to unpack bcachefs-tools_1.31.3_amd64.deb ...
Unpacking bcachefs-tools (1:1.31.3) over (1:1.31.3) ...
Setting up bcachefs-tools (1:1.31.3) ...
Processing triggers for man-db (2.13.1-1) ...
$ eatmydata sudo dpkg -i bcachefs-kernel-dkms_1.31.3_amd64.deb
ERROR: ld.so: object 'libeatmydata.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
(Reading database ... 552274 files and directories currently installed.)
Preparing to unpack bcachefs-kernel-dkms_1.31.3_amd64.deb ...
Unpacking bcachefs-kernel-dkms (1:1.31.3) ...
Setting up bcachefs-kernel-dkms (1:1.31.3) ...
Loading new bcachefs/1.31.1 DKMS files...
Building for 6.16.7+deb14-amd64

Building initial module bcachefs/1.31.1 for 6.16.7+deb14-amd64
Sign command: /lib/modules/6.16.7+deb14-amd64/build/scripts/sign-file
Signing key: /var/lib/dkms/mok.key
Public certificate (MOK): /var/lib/dkms/mok.pub
Certificate or key are missing, generating self signed certificate for MOK...

Building module(s)...... done.
Signing module /var/lib/dkms/bcachefs/1.31.1/build/src/fs/bcachefs/bcachefs.ko
Found pre-existing /lib/modules/6.16.7+deb14-amd64/kernel/fs/bcachefs/bcachefs.ko.xz, archiving for uninstallation
Installing /lib/modules/6.16.7+deb14-amd64/updates/dkms/bcachefs.ko.xz
Running depmod.... done.
Processing triggers for initramfs-tools (0.150) ...
update-initramfs: Generating /boot/initrd.img-6.16.7+deb14-amd64
update-initramfs: Generating /boot/initrd.img-6.12.38+deb13-amd64
$ lsinitramfs -l /boot/initrd.img-6.16.7+deb14-amd64 | grep bcachefs
-rw-r--r--   1 root     root      1027492 Sep 18 04:15 usr/lib/modules/6.16.7+deb14-amd64/updates/dkms/bcachefs.ko.xz
-rwxr-xr-x   1 root     root         2042 Sep 18 03:01 scripts/local-premount/bcachefs
-rwxr-xr-x   1 root     root      3791344 Sep 18 03:01 usr/sbin/bcachefs
lrwxrwxrwx   1 root     root            8 Sep 18 04:15 usr/sbin/mount.bcachefs -> bcachefs

```

Signed-off-by: Roman Lebedev <lebedev.ri@gmail.com>

debian/bcachefs-kernel-dkms.install

@@ -0,0 +1,3 @@
+usr/share/initramfs-tools/hooks/bcachefs
+usr/share/initramfs-tools/scripts/local-premount/bcachefs
+usr/src/bcachefs-*

debian/bcachefs-tools.install

@@ -0,0 +1,9 @@
+usr/lib/udev/rules.d/64-bcachefs.rules
+usr/sbin/bcachefs
+usr/sbin/fsck.bcachefs
+usr/sbin/fsck.fuse.bcachefs
+usr/sbin/mkfs.bcachefs
+usr/sbin/mkfs.fuse.bcachefs
+usr/sbin/mount.bcachefs
+usr/sbin/mount.fuse.bcachefs
+usr/share/man/man8/bcachefs.8

debian/bcachefs-tools.postinst

@@ -1,14 +0,0 @@
-#!/bin/sh
-
-set -e
-
-#DEBHELPER#
-
-case "$1" in
-    configure)
-	if which update-initramfs >/dev/null; then
-	    update-initramfs -u
-	fi
-    ;;
-esac
-

debian/bcachefs-tools.postrm

@@ -1,14 +0,0 @@
-#!/bin/sh
-
-set -e
-
-#DEBHELPER#
-
-case "$1" in
-    remove)
-	if which update-initramfs >/dev/null; then
-	    update-initramfs -u
-	fi
-    ;;
-esac
-

debian/bcachefs.triggers

@@ -1 +0,0 @@
-activate update-initramfs

debian/changelog

@@ -1,8 +1,14 @@
+bcachefs-tools (1:1.31.1~1) unstable; urgency=medium
+
+  * Split DKMS into separate binary package
+
+ -- Roman Lebedev <lebedev.ri@gmail.com>  Thu, 18 Sep 2025 03:01:17 +0300
+
 bcachefs-tools (1:1.31.1) unstable; urgency=medium
 
   * DKMS support
 
- -- Kent Overstreet <kent.overstreet@linux.dev> Wed Sep 17 06:31:34 PM EDT 2025
+ -- Kent Overstreet <kent.overstreet@linux.dev>  Wed, 17 Sep 2025 18:31:34 -0400
 
 bcachefs-tools (1:1.31.0) unstable; urgency=medium
 

debian/control

@@ -26,17 +26,61 @@ Build-Depends: debhelper-compat (= 13),
                uuid-dev,
                zlib1g-dev,
 Homepage: https://bcachefs.org/
-Vcs-Git: https://salsa.debian.org/debian/bcachefs-tools.git
-Vcs-Browser: https://salsa.debian.org/debian/bcachefs-tools
+Vcs-Git: git://evilpiepirate.org/bcachefs-tools.git
+Vcs-Browser: https://evilpiepirate.org/git/bcachefs-tools.git
 
 Package: bcachefs-tools
 Architecture: linux-any
 Depends: ${shlibs:Depends}, ${misc:Depends}, python3:any
-Recommends: initramfs-tools | linux-initramfs-tool
+Recommends: bcachefs-kernel-dkms (= ${binary:Version}),
+            initramfs-tools | linux-initramfs-tool,
+Breaks: bcachefs-kernel-dkms (<< ${binary:Version}),
+        bcachefs-kernel-dkms (>> ${binary:Version}),
 Description: bcachefs userspace tools
  Userspace tools for bcachefs, a modern copy on write, checksumming, multi
  device filesystem.
  .
  Note: The current Debian kernels do not come with bcachefs support, you
- will have to use your own kernel or one provided by a 3rd party that
- contains bcachefs support.
+ will have to install bcachefs-kernel-dkms package or build your own kernel
+ or one provided by a 3rd party that contains bcachefs support.
+
+Package: bcachefs-kernel-dkms
+Architecture: linux-any
+Depends: ${shlibs:Depends}, ${misc:Depends},
+	 initramfs-tools | linux-initramfs-tool,
+	 linux-headers-amd64 [amd64],
+	 linux-headers-arm64 [arm64],
+Pre-Depends: bcachefs-tools (= ${binary:Version}),
+Provides: bcachefs-kernel
+Description: bcachefs kernel module DKMS source
+ "The COW filesystem for Linux that won't eat your data".
+ .
+ Bcachefs is an advanced new filesystem for Linux, with an emphasis
+ on reliability and robustness and the complete set of features
+ one would expect from a modern filesystem.
+ .
+  * Copy on write (COW) - like zfs
+  * Full data and metadata checksumming, for full data integrity:
+    the filesystem should always detect (and where possible,
+    recover from) damage; it should never return incorrect data.
+  * Multiple devices
+  * Replication
+  * Erasure coding (incomplete) High performance: doesn't fragment
+    your writes (like ZFS), no RAID hole
+  * Caching, data placement
+  * Compression
+  * Encryption
+  * Snapshots
+  * Nocow mode
+  * Reflink
+  * Extended attributes, ACLs, quotas
+  * Petabyte scalability
+  * Full online fsck, check and repair (in progress)
+  * Robustness and rock solid repair. Damage and breakage are a fact of life,
+    it's not a matter of if, but when. It doesn't matter what happened
+    to the filesystem: bad hardware, lightning strikes, an errant dd,
+    you can expect that bcachefs will repair the damage and keep going,
+    usually with no user intervention required.
+ .
+ It's the job of the filesystem to never lose your data:
+ anything that can be repaired, will be.