Add persistent script storage + hot-reload, verified live

lua_runtime now loads the running script from a new LittleFS-backed
drivers::storage (joltwallet/littlefs, the project's fifth external
managed component -- mounts the "storage" partition already reserved
in partitions.csv), falling back to the compiled-in default script
only on first boot. transport exposes GET/POST /api/script -- raw Lua
text, not JSON, since json_helpers.h can't round-trip scripts safely
-- relayed to lua_runtime via the same callback-registration pattern
already used for LedColorHandler, keeping transport free of a
dependency on lua_runtime. lua_runtime_reload() persists and hot-swaps
to a fresh Lua state immediately, no reboot.

Verified on real ESP32-C6 hardware: script loads via kvida-sdk, an
edited script hot-reloads within one tick, and the edit survives a
power cycle (proving LittleFS persistence, not just an in-RAM change).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

components/drivers/CMakeLists.txt

@@ -1,5 +1,5 @@
 idf_component_register(
-    SRCS "src/chip_temperature.cpp" "src/rgb_led.cpp"
+    SRCS "src/chip_temperature.cpp" "src/rgb_led.cpp" "src/storage.cpp"
     INCLUDE_DIRS "include"
-    PRIV_REQUIRES esp_driver_tsens espressif__led_strip
+    PRIV_REQUIRES esp_driver_tsens espressif__led_strip joltwallet__littlefs
 )