test(nx): move ROM-free NX suites into the engine tier

platform_nx_* and rom_importer_nx_* run with the love stub and must execute
in CI's ROM-free lane via tests/run_engine.lua, not only T3.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/switch-development.md

@@ -519,7 +519,7 @@ Each slice should declare: **no ROM/save bytes committed**, **love-nx pin with m
 
 - `src/core/Platform.lua`, `conf.lua` NX branch
 - `src/import/RomImporter.lua` (NX flags, inbox, scan, shell/updater gates)
-- Tests: `tests/platform_nx_*`, `tests/rom_importer_nx_*`
+- Tests: `tests/engine/platform_nx_*`, `tests/engine/rom_importer_nx_*` (ROM-free T2)
 - Docs: inbox/MTP import sections only
 
 ### Slice 2 — Input + lifecycle (`input/lifecycle`)

tests/engine/platform_nx_test.lua

@@ -1,5 +1,5 @@
 -- NX / Android / desktop capability detection (SWNX-01).
--- Self-contained: luajit tests/platform_nx_test.lua
+-- Self-contained: luajit tests/engine/platform_nx_test.lua
 
 package.path = "./?.lua;./?/init.lua;" .. package.path
 

tests/run_tests.lua

@@ -3376,13 +3376,8 @@ runSuites({ "tests/rom_importer_android_mod_pick_test.lua" })
 runSuites({ "tests/rom_importer_no_picker_test.lua" })
 runSuites({ "tests/rom_importer_double_pick_test.lua" })
 -- ---------------------------------------------- Switch platform capabilities
-runSuites({ "tests/platform_nx_test.lua" })
+-- platform_nx_* / rom_importer_nx_* live in tests/engine/ (ROM-free T2) so
-runSuites({ "tests/platform_nx_shell_gate_test.lua" })
+-- CI's headless lane runs them without data/generated/.
-runSuites({ "tests/platform_nx_network_gate_test.lua" })
-runSuites({ "tests/rom_importer_nx_flags_test.lua" })
-runSuites({ "tests/rom_importer_nx_inbox_test.lua" })
-runSuites({ "tests/rom_importer_nx_mods_inbox_test.lua" })
-runSuites({ "tests/rom_importer_nx_saves_inbox_test.lua" })
 runSuites({ "tests/launcher_mods_install_zip_test.lua" })
 -- ---------------------------------------------- parity workstream tests
 -- Each tests/parity_*.lua is a self-contained file (own bootstrap + check,