feat: 4-source verified emulator profiles (A-E cores)

33 emulator profiles created or updated with systematic
verification against libretro docs, .info, core source,
and original emulator source code.

New profiles: bsnes-jg, bsnes2014, bsnes_cplusplus98,
bsnes_hd_beta, bsnes_mercury, citra2018, citra_canary.

Key fixes:
- dosbox_svn/svn_ce: not aliases of dosbox_core (no MUNT)
- beetle_psx: alt_names renamed to aliases (field bug)
- dolphin: added 15 Realtek BT firmware for Wiimote passthrough
- dosbox_core: added CM-32LN, 13 split ROM pairs for standalone
- duckstation: type standalone+libretro, 106 BIOS verified
- snes9x/np2kai: formal aliases for alternate filenames

emulators/citra2018.yml

@@ -0,0 +1,43 @@
+emulator: Citra 2018
+type: libretro
+source: "https://github.com/libretro/citra2018"
+upstream: "https://github.com/citra-emu/citra"
+profiled_date: "2026-03-18"
+core_version: "Git"
+display_name: "Nintendo - 3DS (Citra 2018)"
+cores: [citra2018]
+systems:
+  - nintendo-3ds
+
+notes: |
+  Citra 2018 is a 2018 snapshot of the Citra 3DS emulator.
+  Older than current Azahar/Citra — fewer firmware files.
+  Data dir: citra-emu (not azahar-emu).
+  ref: src/common/common_paths.h:24
+
+  Uses RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY.
+  ref: src/citra_libretro/environment.cpp:107
+
+  Loads from sysdata/:
+    aes_keys.txt (not keys.txt like current Citra)
+    shared_font.bin
+  ref: src/core/hw/aes/key.cpp:72-73, src/core/hle/service/apt/apt.cpp:174
+
+  Does NOT load (added in later versions):
+    boot9.bin, sector0x96.bin, seeddb.bin, otp.bin,
+    movable.sed, SecureInfo_A, LocalFriendCodeSeed_B
+
+  firmware_count absent in .info (= 0). Files are optional (HLE).
+
+files:
+  - name: aes_keys.txt
+    system: nintendo-3ds
+    required: false
+    note: "AES encryption keys (named aes_keys.txt, not keys.txt like current Citra)"
+    source_ref: "src/core/hw/aes/key.cpp:72-73"
+
+  - name: shared_font.bin
+    system: nintendo-3ds
+    required: false
+    note: "system shared font, HLE fallback if missing"
+    source_ref: "src/core/hle/service/apt/apt.cpp:174"