feat(cli): numbered selection menus for distributions and versions

Replace the free-text distribution/version prompts with numbered menus via a
shared _choose helper. Name-first resolution keeps typing the name working, so
numeric catalog keys (e.g. arch "4") still select by name, not by position.
Applied to the distribution, arch, manjaro, retropie and raspios choosers.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/unit/test_image_setup.py

@@ -63,6 +63,17 @@ class TestDistributionChoosers:
         with pytest.raises(LimError):
             choosers.choose_linux_image(plan)
 
+    def test_numeric_selection_maps_to_distribution(self, plan, answers):
+        number = str(list(choosers.DISTRIBUTION_CHOOSERS).index("raspios") + 1)
+        answers(number, "lite64")
+        choosers.choose_linux_image(plan)
+        assert plan.distribution == "raspios"
+
+    def test_name_selection_still_works(self, plan, answers):
+        answers("arch", "1")
+        choosers.choose_linux_image(plan)
+        assert plan.distribution == "arch"
+
 
 class TestPartitionInput:
     def test_contains_boot_size_and_writes_table(self):