feat: add 10 emulator profiles (batch 6)

gpsp (GBA, open BIOS fallback), ecwolf (ecwolf.pk3),
prboom (prboom.wad), x1 (Sharp X1, 5 files in xmil/),
minivmac (MacII.ROM/MacIIx.ROM), theodore (Thomson, all embedded),
crocods (CPC 6128, all embedded), vba_next (GBA, HLE fallback),
same_cdi (CD-i, 3 MAME ZIPs + 2 undeclared), beetle_lynx (lynxboot.img)

71 total profiles. Cross-reference: 690 undeclared, 186 in repo.

emulators/gpsp.yml

@@ -0,0 +1,65 @@
+emulator: gpSP
+type: libretro
+source: "https://github.com/libretro/gpsp"
+cores:
+  - gpsp
+systems:
+  - nintendo-gba
+
+notes: |
+  gpSP is a Game Boy Advance emulator originally by Exophase, ported to
+  libretro. Historically it required the official GBA BIOS to run. Current
+  versions ship a built-in open-source BIOS (bios/open_gba_bios.bin) compiled
+  from bios/source/ that covers most games.
+
+  The core option gpsp_bios controls BIOS selection:
+    auto     (default) - try official gba_bios.bin, fall back to built-in
+    builtin  - always use the built-in open-source BIOS
+    official - try gba_bios.bin, warn and fall back to built-in if missing
+
+  A second option gpsp_boot_mode selects startup behavior:
+    game (default) - skip BIOS intro, boot directly into game
+    bios           - run the BIOS boot animation before launching
+
+  BIOS loading path (libretro/libretro.c:1093-1131):
+    1. Resolve system directory (RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY)
+    2. Append "/gba_bios.bin"
+    3. load_bios() reads 0x4000 (16 KB) into bios_rom[]
+    4. Sanity check: bios_rom[0] must be 0x18 (ARM branch opcode)
+    5. On failure, memcpy open_gba_bios_rom[] as fallback
+
+  The official BIOS improves compatibility for a few games that rely on
+  precise SWI behavior or BIOS checksum verification. The built-in BIOS
+  works for the vast majority of the GBA library.
+
+files:
+  # -------------------------------------------------------
+  # Game Boy Advance - BIOS (optional, built-in fallback)
+  # -------------------------------------------------------
+  - name: gba_bios.bin
+    system: nintendo-gba
+    required: false
+    size: 16384  # 16 KB (0x4000)
+    note: "Official GBA BIOS. Built-in open-source BIOS used as fallback. Real BIOS needed for full SWI accuracy and boot logo."
+    source_ref: "libretro/libretro.c:1111"
+
+platform_details:
+  gba:
+    bios_size: 16384  # 16 KB
+    hle_bios: true
+    source_ref: "libretro/libretro.c:1107-1131, bios/source/"
+    notes: |
+      The built-in BIOS (open_gba_bios_rom, 16 KB) is an open-source
+      reimplementation compiled from bios/source/. It implements most
+      SWI calls (SoftReset, RegisterRamReset, Halt, VBlankIntrWait,
+      arithmetic, decompression, sound, multiboot).
+
+      Validation is minimal: load_bios() in gba_memory.c reads exactly
+      0x4000 bytes. The libretro frontend checks bios_rom[0] == 0x18
+      (ARM branch instruction at reset vector) to reject garbage files.
+      No hash or checksum verification is performed.
+
+      The bios_type enum (main.h:56-61) defines three modes:
+        auto_detect  - try official first, fall back to built-in
+        builtin_bios - skip file load entirely, use open_gba_bios_rom
+        official_bios - try file, warn on failure, still fall back