libs/kaptan-stm32f7: add STM32F722 crate shell

libs/kaptan-stm32f7/src/lib.rs

@@ -0,0 +1,14 @@
+//! STM32F7 peripheral drivers used by Kaptan boards.
+//!
+//! This crate is organized by MCU variant and peripheral route. A board chooses
+//! an MCU feature, owns its pin muxing and RTIC interrupt graph, then composes
+//! the typed peripheral drivers from the selected module. Generic telemetry
+//! policy and frame ownership deliberately do not belong here.
+
+#![no_std]
+
+#[cfg(not(feature = "stm32f722"))]
+compile_error!("select one supported STM32F7 variant feature, such as `stm32f722`");
+
+#[cfg(feature = "stm32f722")]
+pub mod stm32f722;