[LNPANDY]

Summary

Stacked on top of #1215 (refactor/patch-slim-phase2). Delivers the refined, zero-engine-patch version of #1080 and #947 across macOS (NXCore / NXModel / NXLauncher), Windows/Qt (nspb_qt), and iOS (ShellHost):

1. Non-polluting externalization of oversized msl/ shader trees (> 64 MiB, fixes Ocarina of Time (NUP) shared-app IPA: 7 GB msl shader image can't be installed by Sideloadly, AltServer or AltStore; romfs.id "cannot be read" after install #947):

   • When packing an unsigned shared IPA (NX2Apple.ipa), any staged game framework whose msl/ directory exceeds 64 MiB has its staged msl/ replaced with external-msl.json ({"schema": 1, "external_msl": true}) and records its title ID in <shellRoot>/export/external-msl-titles.json, keeping the unsigned IPA well below sideloaders' 2 GB / 4 GB limits while leaving <shellRoot>/frameworks/DmGame<ID>.framework/msl/ untouched in place.
   • Packed game data archives (<archive>/<ID>/) remain clean without copying msl/ into them, preventing direct Xcode-signed installs from duplicating bundled shaders onto the device.
   • During unsigned-IPA transfers (ShellInstall.transferSources on macOS and DriveCopy.collect_transfer_files on Windows/Qt), externalized msl/ files are merged on the fly from the mirrored framework into <dest>/<ID>/msl/... for both device (devicectl) and external drive copies.
   • On iOS (ShellHost), ExternalShaders recursively inspects Documents/games/<ID>/msl and <dataURL>/msl (rejecting any incomplete .nxpart, .nxjoin, .part, or .partial entries while ignoring harmless hidden metadata), blocks launch with .needsGameData when required external shaders are missing or half-transferred, and wires EngineLaunchPlan to resolve DM_MSL_DIR from appFolder/msl -> dataURL/msl -> bundled framework msl.

2. No-rebuild shared IPA repack with stale-engine preflight:

   • Exposes Export IPA directly in Step 1 on both macOS (ExportSteps.swift) and Windows/Qt (ui.py + win/shell_export.py:repack_built_shell) so users can repack NX2Apple.ipa from already-built frameworks in shell.json without rebuilding any game.
   • Adds stale_frameworks preflight checks on Windows/Qt matching macOS so repacking warns when cached frameworks come from an older DMSH_CHAIN.

3. Multi-game batch selection for device transfers and external drives:

   • Adds SendSelectedSheet on macOS (for both Device queue transfers and sequential Drive or folder copies with live free-space and FAT32 4 GB preflight checks and cancellation support) and DriveSelectDialog on Windows/Qt, replacing the coarse all-or-nothing action with per-game checkboxes, Select All / Clear toggles, and accurate byte totals (including externalized msl/ trees).
   • Updates all 10 shipped localization catalogs (de, en, es, fr, it, ja, ko, pt-br, sv, zh) and Localizable.xcstrings.

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UI Comparison 1: macOS Launcher (InstallCard & SendSelectedSheet)

Simplified Chinese (zh)

View	Before	After
Export Mode (Device)
Export Mode (Drive or folder)
Select Games Sheet	N/A

English (en)

View	Before	After
Export Mode (Device)
Export Mode (Drive or folder)
Select Games Sheet	N/A

Japanese (ja)

View	Before	After
Export Mode (Device)
Export Mode (Drive or folder)
Select Games Sheet	N/A

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UI Comparison 2: Windows / Qt Launcher (InstallCard & DriveSelectDialog)

Language	Before (InstallCard)	After (InstallCard)	After (DriveSelectDialog)
Chinese (zh)
English (en)
Japanese (ja)

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Verification

• patches/ and .upstream-ref remain completely untouched (0 engine patches added).
• Negative testing verified on iOS (EngineLaunchPlan / ExternalShaders recursive .nxpart check) and Windows/Qt (ExternalMslAndBatchDriveCopyTest) prior to restoring fixes.
• Passed python3 tools/l10n_shell_catalogs.py --check, frontend-ios ShaderResourcesTests & EngineLaunchPlanTests, frontend-qt full unittest suite (including test_localization_rules.py and test_win_shell_export.py), and frontend full swift test suite (including LauncherControlWidthTests across all 10 languages and SourceSizeTests).