feat: file dispatch system, file-type icons, multi-instance notepad

- Add extension-based dispatch to driver.storage.filedispatch with typed
  union (variant record THandlerKind = hkMagic/hkExtension)
- Extract file-type icon constants and mapping to core.gfx.fileicons
- Add core.search utility (getFileExtension, fmtFileSize, sortStringArray)
- Generate PUA bitmap icon fonts (32/64/128px) from Font Awesome via
  gen_file_icons.py + compile_icons.sh toolchain
- Integrate file dispatch into file browser (double-click triggers dispatch)
- Register notepad as handler for text file extensions
- Fix init order in app.mgr (filedispatch.init before app inits)
- Refactor notepad from singleton to multi-instance (up to 8 windows)
  using instance array, findStateByWid, and LVGL user_data on msgboxes

toolchain/compile.sh

@@ -26,6 +26,7 @@ declare -a run_steps=(
 	"compile_stub.sh" "Failed to compile stub!"
 	"compile_vergen.sh" "Versions failed to compile"
 	"compile_lvgl.sh" "Failed to compile LVGL!"
+	"compile_icons.sh" "Failed to generate icons!"
 	"compile_wasuro.sh" "Failed to pull Wasuro!"
 	"compile_sources.sh" "Failed to compile FPC Sources!"
 	"compile_link.sh" "Failed linking!"