chore: file QEMU, Roland, Chihiro and Oric

QEMU's 79 files go to QEMU/QEMU and Roland's four loose ROMs to MT-32
and CM-32L. The mt32-roms, soundcanvas-roms and sounddata trees stay as
the code addresses them. Chihiro joins Sega and the Oric joins
Tangerine, the names the site and libretro already use. No destination
held other bytes.

The three QEMU EDK2 images are release assets, and their .gitignore
lines follow them. Database and manifests are regenerated together.
verify --all and cross_reference give the same output once moved paths
are mapped.

tests/test_bios_layout.py

@@ -0,0 +1,60 @@
+"""bios/ is laid out maker, then machine, then files.
+
+QEMU kept 79 files and Roland four at the maker level, so neither had a
+machine page. Chihiro was filed under Microsoft and Sega, and the Oric under
+Oric and Tangerine: one machine, two folders, two pages.
+"""
+
+from __future__ import annotations
+
+import subprocess
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+
+# Files the trees below them address at the maker level, left as they are.
+MAKER_LEVEL = {
+    "RPG Maker/wildmidi.cfg",
+    "ScummVM/scummvm.zip",
+}
+
+# The machines filed under one maker only, and that maker.
+ONE_MAKER = {"Chihiro": "Sega", "Oric": "Tangerine"}
+
+
+def _tracked_and_ignored() -> list[str]:
+    out = subprocess.run(
+        ["git", "ls-files", "--cached", "--others", "bios"],
+        cwd=REPO_ROOT, capture_output=True, text=True, check=True,
+    ).stdout
+    return [line[len("bios/"):] for line in out.splitlines() if line.startswith("bios/")]
+
+
+class MakerThenMachine(unittest.TestCase):
+    def setUp(self):
+        if not (REPO_ROOT / ".git").exists():
+            self.skipTest("not a git checkout")
+        self.paths = _tracked_and_ignored()
+        if not self.paths:
+            self.skipTest("bios/ not present")
+
+    def test_no_file_sits_at_the_maker_level(self):
+        loose = sorted(
+            p for p in self.paths
+            if p.count("/") == 1 and p not in MAKER_LEVEL
+        )
+        self.assertEqual(loose, [])
+
+    def test_one_machine_has_one_maker(self):
+        for machine, maker in ONE_MAKER.items():
+            makers = sorted({
+                p.split("/", 1)[0] for p in self.paths
+                if p.count("/") >= 2 and p.split("/")[1] == machine
+                and p.split("/", 1)[0] != "Other"
+            })
+            self.assertEqual(makers, [maker], machine)
+
+
+if __name__ == "__main__":
+    unittest.main()