fix: split the np2 V98 font from font.bmp

NP2kai and meowPC98 read font.bmp (PC-98 bitmap) and FONT.ROM (V98) as
separate files, each through its own reader (NP2kai font/font.c:192-195,
meowPC98 font/font.c:180-181). The V98 names hung on font.bmp as aliases
let a collection without font.bmp serve the PC-88 2 KB font.rom there.
FONT.ROM is now its own entry, at least 0x46800 bytes (fontv98.c:8, 51).

Manifests: np2/FONT.ROM and np2kai/FONT.ROM are added where the platform
did not declare them, served by the V98 font bios/NEC/PC-98/font.rom.

install/knulli.json

@@ -6,7 +6,7 @@
   "platform": "knulli",
   "display_name": "KNULLI",
   "version": "20260511",
-  "generated": "2026-11-05T12:13:24Z",
+  "generated": "2026-11-05T18:31:29Z",
   "base_destination": "bios",
   "detect": [
     {
@@ -9186,6 +9186,17 @@
       "cores": null,
       "systems": [
         "nec-pc-98"
+      ],
+      "alternatives": [
+        {
+          "sha1": "78ba9960f135372825ab7244b5e4e73a810002ff",
+          "sha256": "8db165d567e13bce3f50ee495975671faa5a0ff332dcb08e187aa91125c81ec6",
+          "size": 288768,
+          "repo_path": "bios/NEC/PC-98/font.rom",
+          "cores": [
+            "np2kai"
+          ]
+        }
       ]
     },
     {