fix: resolve bios case collisions

Delete duplicate lowercase variants (identical MD5) of 12 files
that prevented clean checkout on case-insensitive filesystems
(Windows, macOS).

Canonical chosen per upstream source code:
- Atari 2600 KV*.WAV: uppercase (stella2023 hardcode)
- Vectrex VEC_Minestorm.vec: lowercase (BizHawk hardcode)
- MSX MSX{,2,2EXT}.ROM: uppercase (fMSX hardcode, 6/7 platforms)
- Doom DOOM2.WAD: uppercase (matches dir convention)

Add aliases to stella2014 and clk profiles so resolution still
finds the canonical source. Correct retrodeck Vectrex casing to
match upstream. Merge Commodore/Vic-20 into VIC-20.

Add tests/test_no_case_collisions.py as a CI guard.

Closes #49

database.json

@@ -1,5 +1,5 @@
 {
-  "generated_at": "2026-04-02T12:45:07Z",
+  "generated_at": "2026-04-18T07:32:14Z",
   "total_files": 7302,
   "total_size": 9190488848,
   "files": {
@@ -30814,8 +30814,8 @@
       "adler32": "87461161"
     },
     "65d07426b520ddd3115d40f255511e0fd2e20ae7": {
-      "path": "bios/GCE/Vectrex/VEC_MineStorm.vec",
-      "name": "VEC_MineStorm.vec",
+      "path": "bios/GCE/Vectrex/VEC_Minestorm.vec",
+      "name": "VEC_Minestorm.vec",
       "size": 8192,
       "sha1": "65d07426b520ddd3115d40f255511e0fd2e20ae7",
       "md5": "ab082fa8c8e632dd68589a8c7741388f",
@@ -89077,7 +89077,7 @@
       "VEC_Bios.bin": [
         "b9bbf5bb0eac52d039a4a993a2d8064b862c9e28"
       ],
-      "VEC_MineStorm.vec": [
+      "VEC_Minestorm.vec": [
         "65d07426b520ddd3115d40f255511e0fd2e20ae7"
       ],
       "CHRGEN.BIN": [
@@ -89087,8 +89087,7 @@
         "aea7a4c0c7ffe1f212f7b9faecfd728862ac6904"
       ],
       "doom2.wad": [
-        "6d559b7ceece4f5ad457415049711992370d520a",
-        "7ec7652fcfce8ddc6e801839291f0e28ef1d5ae7"
+        "6d559b7ceece4f5ad457415049711992370d520a"
       ],
       "freedoom1.wad": [
         "97bb88094a51457a8dcad98c58be22a2d0fa9a37"
@@ -101523,27 +101522,6 @@
       "samesame.zip": [
         "cdb09d3ffaa867ff9e7387cf1934e9011565d546"
       ],
-      "kvb1.wav": [
-        "6a582aebcefd6e2a97bdd8968202aab9851a889c"
-      ],
-      "kvb2.wav": [
-        "60a425c6bde3226ab731995562716321be20fc49"
-      ],
-      "kvb3.wav": [
-        "5e34125c4d6c209b21d1c892f3df0ec1644fd0d8"
-      ],
-      "kvs1.wav": [
-        "b094c2c1fca81a0e531e0541f302346150ec4604"
-      ],
-      "kvs2.wav": [
-        "8b83b2eea01b3e08ceb885aeb153d4084bddb63c"
-      ],
-      "kvs3.wav": [
-        "86896a1e272d8715489de9b407f0b8a42f82d4a0"
-      ],
-      "kvshared.wav": [
-        "9adf10cdf1de833b194c7d8797ad1f041ad98dd3"
-      ],
       "atari_osb.rom": [
         "db1031585968cfc6ec2ecda5c9a5a52f61444a3b"
       ],
@@ -101754,18 +101732,18 @@
       "kernal.318004-05.bin": [
         "7c7e07f016391174a557e790c4ef1cbe33512cdb"
       ],
-      "characters-japanese.bin": [
-        "dae61ac03065aa2904af5c123ce821855898c555"
-      ],
-      "kernel-japanese.bin": [
-        "c9ead45e6674d1042ca6199160e8583c23aeac22"
-      ],
       "basic.bin": [
         "587d1e90950675ab6b12d91248a3f0d640d02e8d"
       ],
       "characters-english.bin": [
         "4fd85ab6647ee2ac7ba40f729323f2472d35b9b4"
       ],
+      "characters-japanese.bin": [
+        "dae61ac03065aa2904af5c123ce821855898c555"
+      ],
+      "kernel-japanese.bin": [
+        "c9ead45e6674d1042ca6199160e8583c23aeac22"
+      ],
       "kernel-ntsc.bin": [
         "06de7ec017a5e78bd6746d89c2ecebb646efeb19"
       ],
@@ -101818,9 +101796,6 @@
       "sl90025.bin": [
         "759e2ed31fbde4a2d8daf8b9f3e0dffebc90dae2"
       ],
-      "VEC_Minestorm.vec": [
-        "65d07426b520ddd3115d40f255511e0fd2e20ae7"
-      ],
       "Vectrex_Bios.bin": [
         "b9bbf5bb0eac52d039a4a993a2d8064b862c9e28"
       ],
@@ -101849,15 +101824,6 @@
       "px-7_basic-bios1.rom": [
         "302afb5d8be26c758309ca3df611ae69cced2821"
       ],
-      "msx.rom": [
-        "409e82adac40f6bdd18eb6c84e8b2fbdc7fb5498"
-      ],
-      "Machines/Shared Roms/MSX.rom": [
-        "409e82adac40f6bdd18eb6c84e8b2fbdc7fb5498"
-      ],
-      "msx2.rom": [
-        "6103b39f1e38d1aa2d84b1c3219c44f1abb5436e"
-      ],
       "nms8250_basic-bios2.rom": [
         "6103b39f1e38d1aa2d84b1c3219c44f1abb5436e"
       ],
@@ -101867,9 +101833,6 @@
       "nms8245_basic-bios2.rom": [
         "6103b39f1e38d1aa2d84b1c3219c44f1abb5436e"
       ],
-      "msx2ext.rom": [
-        "5c1f9c7fb655e43d38e5dd1fcc6b942b2ff68b02"
-      ],
       "nms8250_msx2sub.rom": [
         "5c1f9c7fb655e43d38e5dd1fcc6b942b2ff68b02"
       ],
@@ -103332,6 +103295,9 @@
       "EXOS21.ROM": [
         "55315b20fecb4441a07ee4bc5dc7153f396e0a2e"
       ],
+      "Machines/Shared Roms/MSX.rom": [
+        "409e82adac40f6bdd18eb6c84e8b2fbdc7fb5498"
+      ],
       "sony-playstation:239665b1a3dade1b5a52c06338011044": [
         "343883a7b555646da8cee54aadd2795b6e7dd070"
       ],
@@ -132695,14 +132661,12 @@
         "81193965a374d77b99b4743d317824b53c3e3c78",
         "8f70d1b74483ba3a37e86cf16c849d601a8c3d2c",
         "759e2ed31fbde4a2d8daf8b9f3e0dffebc90dae2",
-        "65d07426b520ddd3115d40f255511e0fd2e20ae7",
         "5a65b922b562cb1f57dab51b73151283f0e20c7a",
         "f9608bb4ad1cfe3640d02844c7ad8e0bcd974917",
         "000ac11b702a4c42e40f135df12fa5f2f13e20a1",
         "3656bb3bbc17d280d2016fe4f6ff3cded3082a41",
         "e998f0c441f4f1800ef44e42cd1659150206cf79",
         "302afb5d8be26c758309ca3df611ae69cced2821",
-        "409e82adac40f6bdd18eb6c84e8b2fbdc7fb5498",
         "6103b39f1e38d1aa2d84b1c3219c44f1abb5436e",
         "5c1f9c7fb655e43d38e5dd1fcc6b942b2ff68b02",
         "5aff2d9b6efc723bc395b0f96f0adfa83cc54a49",
@@ -132865,6 +132829,7 @@
         "9451a1a09d8f75944dbd6f91193fc360f1de80ac",
         "03bbb386cf530e804363acdfc1d13e64cf28af2e",
         "55315b20fecb4441a07ee4bc5dc7153f396e0a2e",
+        "409e82adac40f6bdd18eb6c84e8b2fbdc7fb5498",
         "343883a7b555646da8cee54aadd2795b6e7dd070",
         "15c94da3cc5a38a582429575af4198c487fe893c",
         "73107d468fc7cb1d2c5b18b269715dd889ecef06",