feat: add emulator/system pack generation, validation checks, path resolution

add --emulator, --system, --standalone, --list-emulators, --list-systems
to verify.py and generate_pack.py. packs are RTU with data directories,
regional BIOS variants, and archive support.

validation: field per file (size, crc32, md5, sha1) with conflict
detection. by_path_suffix index in database.json for regional variant
resolution via dest_hint. restructure GameCube IPL to regional subdirs.

66 E2E tests, full pipeline verified.

emulators/ishiiruka.yml

@@ -1,10 +1,13 @@
 emulator: Ishiiruka
 type: libretro
+core_classification: enhanced_fork
 source: "https://github.com/libretro/ishiiruka"
-profiled_date: "2026-03-18"
+upstream: "https://github.com/Tinob/Ishiiruka"
+profiled_date: "2026-03-21"
 core_version: "Git"
 display_name: "Nintendo - GameCube / Wii (Ishiiruka)"
-fork_of: Dolphin
+cores:
+  - ishiiruka
 systems: [nintendo-gamecube, nintendo-wii]
 
 # Ishiiruka is a performance-focused Dolphin fork with custom GPU backends.
@@ -19,6 +22,11 @@ systems: [nintendo-gamecube, nintendo-wii]
 
 # Core options use "ishiiruka_" prefix (ishiiruka_dsp_hle, ishiiruka_efb_scale, etc.)
 
+data_directories:
+  - ref: dolphin-sys
+    destination: "dolphin-emu/Sys"
+    source_ref: "Source/Core/Common/CommonPaths.h:115"
+
 files:
   # -- GameCube IPL (Boot ROM) --
   # Region-specific, placed in GC/<region>/IPL.bin