* **Documentation**
* Added new C coding style guide detailing naming conventions for files, directories, macros, constants, variables, functions, and type definitions with illustrative examples.
* Updated C++ coding style documentation with clarifications on C naming conventions and header directory organization patterns.
* **Refactor**
* Updated header include paths throughout the codebase to use lowercase naming conventions consistently.
* **New Features**
* Time and delay utilities added (ticks, ms, µs); SD card now uses an expansion-header CS pin; HTTP downloads warn when run on the GUI task and yield to avoid blocking.
* **Bug Fixes / Reliability**
* Many hard-crash paths converted to guarded checks to reduce abrupt termination and improve stability.
* **Tests**
* Unit tests added to validate time and delay accuracy.
* **Chores**
* License header and build/macro updates.
