docs(wit): document capability and component contracts

components/clock-probe/src/lib.rs

@@ -1,4 +1,12 @@
+//! Example service that imports the versioned Wasmeld monotonic-clock capability.
+//!
+//! Each response is eight little-endian timestamp bytes followed by the input.
+//! The timestamp is Actor-local monotonic time, not a Unix timestamp.
+
 mod bindings {
+    // This macro generates Rust ABI adapters at compile time from the
+    // materialized local WIT graph. It does not make a remote protocol call or
+    // embed the WIT source files; the Component carries canonical ABI types.
     wit_bindgen::generate!({
         path: "wit",
         world: "clock-probe-component",