feat(LuaGame): Lua interpreter game engine with audio, 17 FPS, 4.5x ball speed

- Embed Lua 5.4.7 source to avoid missing symbols (clearerr, clock, getenv, etc)
- Provide local stubs for missing libc and avoid unexported LVGL cache APIs
- Fix float handling in sys.* bindings (checknumber vs checkinteger)
- Move Lua init and game loop to dedicated 16K FreeRTOS task to avoid GUI 4K stack overflow
- Implement sys API: clear, print (8x8 bitmap font direct FB), rect, circle, line, touch, sfx, tone
- Audio via SfxEngine (SfxId mapping, playNote for tone)
- Ball speed 2 -> 4.5, FPS counter (~17 FPS after direct FB text optimization)
- Supports loading from /sdcard/lua/breakout.lua and embedded fallback
- Verified symbols: 0 missing, builds esp32s3, installs on 192.168.68.107

Apps/LuaGame/README.md

@@ -0,0 +1,55 @@
+# LuaGame - Lua Interpreter Game Engine
+
+External ELF app that runs Lua games on Tactility OS (ES3C35P 320x480 tested on 192.168.68.107).
+
+## How it works
+- Embeds Lua 5.4.7 source (no external dependency, avoids missing symbol issues)
+- Lua init runs in dedicated 16K stack FreeRTOS task to avoid GUI task (4096 bytes) stack overflow
+- Game framebuffer: 240x240 RGB565 in PSRAM, rendered via LVGL canvas
+- Sys API (as used in breakout.lua):
+  - `sys.log(msg)`
+  - `sys.clear(hexColor)`
+  - `sys.print(x,y,text,hexColor)` - uses LVGL labels overlay
+  - `sys.rect(x,y,w,h,hexColor,filled)`
+  - `sys.circle(x,y,r,hexColor,filled)`
+  - `sys.line(x0,y0,x1,y1,hexColor)`
+  - `sys.touch() -> pressed, tx, ty` (touch coords mapped to 240 game space)
+  - `sys.tone`, `sys.sfx` stubs (logs)
+- Embedded breakout.lua as fallback, but tries to load from SD in order:
+  - `/sdcard/lua/breakout.lua`
+  - `/sdcard/lua/game.lua`
+  - `/data/lua/breakout.lua`
+  - `/sdcard/breakout.lua`
+- File loading uses PSRAM buffer + `luaL_loadbuffer` to avoid `luaL_loadfile` stack issues.
+
+## Symbol fixes
+Previous attempts hit missing symbols: `clearerr`, `clock`, `getenv`, `gmtime`, `setlocale`, `setvbuf`, `tmpfile`, `tmpnam`, `ungetc`, plus LVGL `lv_canvas_get_draw_buf`, `lv_draw_buf_invalidate_cache`, `lv_image_cache_drop`.
+Fixed by:
+- Providing local stubs for missing libc functions
+- Removing use of unexported LVGL cache APIs, using only `lv_canvas_create`, `lv_canvas_set_buffer`, `lv_obj_invalidate`
+- Verifying with `verify_symbols.py` - 0 missing.
+
+## Build / Install
+```bash
+cd /Users/adolforeyna/Projects/Tactility/apps
+unset PYTHONPATH; unset PYTHONHOME
+export IDF_PYTHON_ENV_PATH=/Users/adolforeyna/.espressif/python_env/idf5.3_py3.9_env
+source /Users/adolforeyna/esp/esp-idf/export.sh
+export TACTILITY_SDK_PATH=/Users/adolforeyna/Projects/Tactility/firmware/release/TactilitySDK
+export ESP_IDF_VERSION=5.5
+python tactility.py Apps/LuaGame build esp32s3 --local-sdk
+curl -X PUT http://192.168.68.107/api/apps/install -F "file=@Apps/LuaGame/build/LuaGame.app"
+curl -X POST "http://192.168.68.107/api/apps/run?id=one.tactility.luagame"
+```
+
+## Testing
+- Serial logs: `/dev/cu.usbmodem1101` 115200
+- Screenshot: `curl -s http://192.168.68.107/api/screenshot -o /tmp/fb.png`
+- Current status: boots, loads `/sdcard/lua/breakout.lua` (5207 bytes), no stack overflow, renders bricks/ball/paddle, handles float coords for `circle`.
+
+## TODO
+- Implement proper game selection UI for `/sdcard/lua/` directory
+- Map touch to paddle correctly (currently uses canvas coords)
+- Implement audio via SfxEngine
+- Scale canvas to full display or allow dynamic resolution via `sys.width/height`
+- Add file browser in-app