lib.Distro.verify(): Add method

jw-base verify pipes the output of rpm -qV for all janware packages
into a grep for md5 mismatches and missing files. The same capability,
distribution-independent, belongs in the Distro abstraction so that tools
like jw-nettools can check the integrity of the packages they install on a
fleet of hosts.

- Add Distro.verify(), which verifies the given package names, or all
  packages selected by the package filter when none are given, and returns
  the flagged files
- Add Distro._verify() as the distribution hook
- Add FlaggedFile, the record for a flagged file: package, file, and the
  package manager's verify status line - not distribution independent as of
  today, but it's a start
- pm/rpm.py: parse_verify_output() parses the output of `rpm -qV` and
  reports md5 mismatches and missing files, the latter reported with the
  literal word "missing" in the flag field; size, mode, mtime, user, and
  group mismatches are noise on dev machines and are ignored.
  verify_packages() runs `rpm -qV` per package and collects the findings
- pm/dpkg.py: parse_verify_output() parses the output of `dpkg -V` and
  reports md5sum (P) mismatches and missing files (M); verify_packages()
  runs `dpkg -V` per package
- The SUSE, Red Hat, and Debian Distro classes implement _verify() with the
  respective pm helpers; the Arch Distro raises NotImplementedError, like
  its other package manager hooks

Signed-off-by: Jan Lindemann <jan@janware.com>
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v1.2.0

test/unit/python/jw/pkg/lib/pm/rpm/Makefile

@@ -0,0 +1,7 @@
+TOPDIR = ../../../../../../../..
+
+include $(TOPDIR)/make/proj.mk
+include $(JWBDIR)/make/py-run.mk
+
+all:
+test: run

test/unit/python/jw/pkg/lib/pm/rpm/test.py

@@ -0,0 +1,58 @@
+from __future__ import annotations
+
+from jw.pkg.lib.FlaggedFile import FlaggedFile
+from jw.pkg.lib.pm.rpm import _parse_verify_output
+
+# -- _parse_verify_output --
+
+# -- A clean line is not reported
+assert _parse_verify_output('pkg', '.....UG..    /usr/bin/foo\n') == []
+
+# -- Mismatches in size, mode, mtime, user, and group are noise
+assert _parse_verify_output('pkg', 'SM...UGT.  c /etc/foo\n') == []
+
+# -- A content (md5) mismatch is reported, with the flags preserved
+ret = _parse_verify_output('pkg', 'SM5....T.  c /etc/foo\n')
+assert len(ret) == 1
+assert ret[0].pkg == 'pkg'
+assert ret[0].file == '/etc/foo'
+assert ret[0].flags == 'SM5....T.'
+
+# -- The 8-character flag layout of older rpm versions is understood
+ret = _parse_verify_output('pkg', 'SM5....T /etc/foo\n')
+assert len(ret) == 1
+assert ret[0].flags == 'SM5....T'
+
+# -- A missing file is reported, config files included
+ret = _parse_verify_output('pkg', 'missing     /etc/opt/jw-ws/pi\n')
+assert len(ret) == 1
+assert ret[0].file == '/etc/opt/jw-ws/pi'
+assert ret[0].flags == 'missing'
+ret = _parse_verify_output('pkg', 'missing   c /etc/opt/jw-ws/pi/models.json\n')
+assert len(ret) == 1
+assert ret[0].file == '/etc/opt/jw-ws/pi/models.json'
+
+# -- A trailing parenthesized annotation is not part of the file
+# name
+ret = _parse_verify_output(
+    'pkg', 'missing   c /etc/phpMyAdmin/config.inc.php.jw-tmpl (Permission denied)\n'
+)
+assert len(ret) == 1
+assert ret[0].file == '/etc/phpMyAdmin/config.inc.php.jw-tmpl'
+
+# -- Lines without a file name and foreign output are ignored
+assert _parse_verify_output('pkg', '.....UG..\n') == []
+assert _parse_verify_output('pkg', 'package foo is not installed\n') == []
+assert _parse_verify_output('pkg', 'error: rpm verify failed\n') == []
+
+# -- The output of several files is accumulated
+ret = _parse_verify_output(
+    'pkg', 'SM5....T.  c /etc/foo\nmissing   c /etc/bar\n.....UG..  c /etc/baz\n'
+)
+assert [f.file for f in ret] == ['/etc/foo', '/etc/bar']
+
+# -- FlaggedFile renders as pkg file flags
+f = FlaggedFile('pkg', '/etc/foo', 'SM5....T.')
+assert repr(f) == 'pkg /etc/foo SM5....T.'
+
+print('All rpm pm tests passed')