feat: read Recalbox launchers from configgen

The scraper now records, from configgen at the pinned tag, the names each Recalbox launcher tries and where it hands them: the Hatari TOS cascades (standalone, hatari and hatarib cores), GSplus, Amiberry kickstarts, the PCSX2 region choice, the Dolphin IPL presence test, xemu, the mupen64plus 64DD IPL, the Mini vMac boot disk and the o2em_bios option. The system_directory libretroRetroarch gives each core, and the per-system overrides after it, are passes_path records.

wiki/adding-a-platform.md

@@ -258,6 +258,13 @@ seven BIOS paths on every device but AMD64, where the keys are left empty:
 An extractor that no longer recognises the shape of the code raises: an
 empty list would read as a launcher that looks for nothing.
 
+A libretro frontend that picks the system directory per core records each
+choice as a `passes_path` entry with no `names`. Recalbox gives gpsp
+`bios/gba` and geargrafx `bios/pcenginecd`, so a core that opens `gba_bios.bin`
+reads it from there. `emulator: libretro` stands for every core Recalbox runs,
+for the default directory and for the per-system overrides applied after the
+per-core choice, and `<system>` in `search_dir` is the system's own name.
+
 ### Inheritance
 
 If the new platform inherits from an existing one (e.g. Lakka inherits RetroArch),