feat: hle_fallback on 39 emulator profiles (266 entries)

Batch analysis of all 273 profiles to identify HLE/embedded
fallbacks. Added hle_fallback: true where the core has verified
software replacement for missing BIOS files:

- Embedded ROMs: vice (102), ep128emu (22), fuse (18), frodo (4)
- HLE BIOS: bsnes* (33 across 3 profiles), puae (9 AROS),
  noods (4), melonds* (6 FreeBIOS), flycast (3 reios)
- Open-source replacements: sameboy (8), pokemini (1), gpsp (1)
- Built-in fallbacks: np2kai (7), atari800 (6 Altirra),
  picodrive (3), quasi88 (4), gambatte (2)

Conservative: only added where notes or source code confirm HLE.
Skipped 50+ profiles where files are optional alternatives, not
HLE replaceable (neocd, opera, kronos, pcem, etc.)

emulators/pcsx2.yml

@@ -74,6 +74,7 @@ files:
   - name: "<biosname>.nvm"
     pattern: "{biosbase}.nvm"
     required: false
+    hle_fallback: true
     size: 1024  # NVRAM_SIZE = 1024 bytes
     source_ref: "pcsx2/CDVD/CDVD.cpp:160-238"
     note: >
@@ -86,6 +87,7 @@ files:
   - name: "<biosname>.mec"
     pattern: "{biosbase}.mec"
     required: false
+    hle_fallback: true
     size: 4  # u32 s_mecha_version
     source_ref: "pcsx2/CDVD/CDVD.cpp:190-204"
     note: >
@@ -106,6 +108,7 @@ files:
   # -- DEV9 EEPROM (optional, network adapter) --
   - name: "eeprom.dat"
     required: false
+    hle_fallback: true
     size: 64  # 64 bytes, mmap'd
     source_ref: "pcsx2/DEV9/DEV9.cpp:110-160"
     note: >