docs(wit): document capability and component contracts

components/counter/src/lib.rs

@@ -1,6 +1,14 @@
+//! Minimal stateful Component used to demonstrate a warm Actor Store.
+//!
+//! Invoke returns an eight-byte little-endian counter. The value survives
+//! calls to the same Actor but resets on `init`, restart, or process recovery.
+
 use core::sync::atomic::{AtomicU64, Ordering};
 
 mod bindings {
+    // Bindings are generated from `wit/world.wit` plus materialized
+    // `wit/deps`; WIT is a compile-time ABI contract, not downloaded at run
+    // time and not executed as code.
     wit_bindgen::generate!({
         path: "wit",
         world: "counter-component",

components/counter/wit.lock

@@ -4,5 +4,5 @@ schema_version = 1
 name = "wasmeld:service"
 version = "0.1.0"
 source = "path+../../wit/service"
-sha256 = "d5497307bbcd1e159f7707f385b488a6f2e26362d5256d5bc1080ac603a51305"
+sha256 = "1b2069606ccbf5202789667570bc824f702f34b147aa38e81c2ab677444ffa0e"
 replaced = true

components/counter/wit/world.wit

@@ -1,5 +1,6 @@
 package component:counter@0.1.0;
 
+/// Counter only needs the base service lifecycle and imports no Host capability.
 world counter-component {
   include wasmeld:service/service-component@0.1.0;
 }