Add a --verbose option to the mvt, mvt-ios and mvt-android commands

Verbosity was an option of each module-running command, so
"mvt-ios --verbose check-backup" was a usage error, a plugin command had to
define a flag of its own, and there was no way to get debug output from mvt at
all.

The option now sits on the three commands themselves and sets the level of
MVT's console handler for the run, through set_verbose_logging(), before any
command runs. Plugin commands registered on any of the three CLIs get the
option for free and need none of their own.

The per-command --verbose of the check-* commands is kept for backward
compatibility. It only ever raises the level, so the CLI's choice is never
undone by a command's default, and its help text says it is kept for
compatibility. It is to be removed in a later release.

tests/test_cli_verbose.py

@@ -0,0 +1,107 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2026 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+
+import logging
+
+import pytest
+from click.testing import CliRunner
+
+from mvt.android.cli import cli as android_cli
+from mvt.cli import cli as mvt_cli
+from mvt.common.log import MVTLogHandler
+from mvt.common.utils import set_verbose_logging
+from mvt.ios.cli import cli as ios_cli
+
+# Keep the banner of the group callback from checking for updates online.
+OFFLINE = ["--disable-update-check", "--disable-indicator-update-check"]
+
+PROGRAMS = {"mvt": mvt_cli, "mvt-ios": ios_cli, "mvt-android": android_cli}
+
+
+@pytest.fixture(autouse=True)
+def _reset_console_level():
+    """Leave the console handler at its default level after every test."""
+    yield
+    set_verbose_logging(False)
+
+
+def _console_level():
+    """Return the level of MVT's own console log handler."""
+    for handler in logging.getLogger("mvt").handlers:
+        if isinstance(handler, MVTLogHandler):
+            return handler.level
+    raise AssertionError("MVT has no console log handler")
+
+
+class TestVerboseOnTheCommands:
+    @pytest.mark.parametrize("program", sorted(PROGRAMS))
+    def test_verbose_before_the_command_name_turns_on_debug(self, program):
+        cli = PROGRAMS[program]
+
+        result = CliRunner().invoke(cli, [*OFFLINE, "--verbose", "version"])
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.DEBUG
+
+    @pytest.mark.parametrize("program", sorted(PROGRAMS))
+    def test_a_run_without_verbose_goes_back_to_info(self, program):
+        cli = PROGRAMS[program]
+        CliRunner().invoke(cli, [*OFFLINE, "--verbose", "version"])
+
+        result = CliRunner().invoke(cli, [*OFFLINE, "version"])
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.INFO
+
+    def test_mvt_verbose_without_a_command_prints_the_help(self):
+        result = CliRunner().invoke(mvt_cli, [*OFFLINE, "--verbose"])
+
+        assert result.exit_code == 0
+        assert "Usage:" in result.output
+        assert _console_level() == logging.DEBUG
+
+
+class TestVerboseOnTheCheckCommands:
+    def test_ios_command_default_does_not_undo_the_cli_choice(self, tmp_path):
+        result = CliRunner().invoke(
+            ios_cli,
+            [*OFFLINE, "--verbose", "check-backup", "--list-modules", str(tmp_path)],
+        )
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.DEBUG
+
+    def test_ios_verbose_after_the_command_name_still_works(self, tmp_path):
+        result = CliRunner().invoke(
+            ios_cli,
+            [*OFFLINE, "check-backup", "--verbose", "--list-modules", str(tmp_path)],
+        )
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.DEBUG
+
+    def test_android_command_default_does_not_undo_the_cli_choice(self, tmp_path):
+        result = CliRunner().invoke(
+            android_cli,
+            [*OFFLINE, "--verbose", "check-bugreport", "--list-modules", str(tmp_path)],
+        )
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.DEBUG
+
+    def test_android_verbose_after_the_command_name_still_works(self, tmp_path):
+        result = CliRunner().invoke(
+            android_cli,
+            [*OFFLINE, "check-bugreport", "--verbose", "--list-modules", str(tmp_path)],
+        )
+
+        assert result.exit_code == 0
+        assert _console_level() == logging.DEBUG
+
+    def test_the_command_option_says_it_is_kept_for_compatibility(self):
+        result = CliRunner().invoke(ios_cli, [*OFFLINE, "check-backup", "--help"])
+
+        assert result.exit_code == 0
+        assert "kept for compatibility" in result.output