feat: one card list and one card check

Every system that runs from its SD card comes from card_setups(),
derived from the device rules: the setup list, its filter, --platform
and the line menus give each its own row and ask for its card. The
RetroArch row no longer lists handheld systems.

card_root_folder and card_choice share one identity check: another
system's card is refused for every system, KNULLI and ROCKNIX included,
and the same --dest gives the same folder from every entry point. WSL
drive letters are read as typed, the line question lists only that
system's cards and asks again after no.

Offline at a terminal, files left out count as missing: the run ends
with code 1 or 2, as the full screen does. Continue on the systems list
opens Confirm. Wording and layout points of code_audit_13 and
tui_audit_6.

tests/test_install_offline.py

@@ -779,5 +779,69 @@ class ADryRunOpensOnItsTotals(Scratch):
         self.assertTrue(any("sys00/file0.bin" in line for line in plan))
 
 
+
+class OfflineLeavesFilesMissing(Scratch):
+    """code_audit_13 P1-1, P3-7, P3-8: the files --offline leaves out at a
+    terminal were counted with a "no" to the size question. Once one file
+    came from this machine, 14,696 missing ended on Done and exit 0."""
+
+    def outcome(self, **counts) -> tuple[int, str]:
+        out = io.StringIO()
+        with contextlib.redirect_stdout(out), self.assertRaises(SystemExit) as stop:
+            install._report_outcome([self.dest], counts.get("installed", 0), 0,
+                                    counts.get("errors", 0), 0, False,
+                                    sources=counts.get("sources", ""),
+                                    offline=counts["offline"])
+        return stop.exception.code, out.getvalue()
+
+    def test_some_installed_is_not_done(self):
+        code, text = self.outcome(installed=4, offline=14696,
+                                  sources="4 files copied from old, 14696 still missing.")
+        self.assertEqual(code, 1)
+        self.assertNotIn("Done", text)
+        self.assertIn("Finished with files missing. 4 files installed, 14696 not fetched "
+                      "(--offline).", text)
+        self.assertIn("14696 still missing", text)
+
+    def test_nothing_installed_is_code_2(self):
+        code, text = self.outcome(offline=14700)
+        self.assertEqual(code, 2)
+        self.assertIn("Nothing installed: 14700 files need the internet, which --offline "
+                      "does not use.", text)
+        # Nothing was up to date: the line said "0 files already up to date".
+        self.assertNotIn("up to date", text)
+
+    def test_the_folder_given_is_not_suggested_again(self):
+        old = self.root / "old"
+        old.mkdir()
+        install.LOCAL.reset()
+        self.addCleanup(install.LOCAL.reset)
+        install.LOCAL.folders = [install.FolderIndex(old)]
+        _code, text = self.outcome(offline=3)
+        self.assertIn(f"They are not in {old}", text)
+        self.assertNotIn("(--from)", text)
+
+    def test_a_dry_run_offline_says_no_download(self):
+        proc = self.run_installer("--offline", "--dry-run", "--manifest", str(self.list))
+        self.assertEqual(proc.returncode, 0, proc.stdout + proc.stderr)
+        self.assertNotIn("Would download", proc.stdout)
+        self.assertIn("4 files (", proc.stdout)
+        self.assertIn("need the internet, which --offline does not use. Without --offline "
+                      "they would go to", proc.stdout)
+
+    def test_an_archive_not_read_is_only_its_error(self):
+        listed = manifest()
+        listed["data_directories"] = [{
+            "ref": "bluemsx", "dest": "Machines", "type": "zip",
+            "url": "https://example.invalid/blueMSX.zip", "systems": ["nintendo-gba"],
+            "files": {"a.txt": {"sha1": _sha1(b"a"), "size": 1}},
+        }]
+        self.list.write_text(json.dumps(listed))
+        self.complete()
+        proc = self.run_installer("--offline", "--manifest", str(self.list), "--no-input")
+        self.assertIn("bluemsx: could not read", proc.stderr)
+        self.assertNotIn("no longer in the source", proc.stdout)
+
+
 if __name__ == "__main__":
     unittest.main()