feat: prepare agen crates for publication

crates/agen-macros/README.md

@@ -0,0 +1,32 @@
+# agen-macros
+
+Procedural macros used by [`agen`](https://crates.io/crates/agen) to declare LLM tools from Rust methods.
+
+Applications should normally depend only on `agen` and import its re-exports:
+
+```rust
+use agen::tool_registry;
+
+#[derive(Clone)]
+struct Tools;
+
+#[tool_registry]
+impl Tools {
+    /// Returns the supplied text.
+    #[tool]
+    async fn echo(
+        &self,
+        #[description = "Text to return"] text: String,
+    ) -> Result<String, std::io::Error> {
+        Ok(text)
+    }
+}
+```
+
+`#[tool_registry]` generates the argument schema, a `Tool` implementation, and an `<method>_definition` constructor. It rejects arguments of its own, duplicate `#[tool]` markers, malformed or duplicate `#[description = "..."]` attributes, and non-identifier argument patterns.
+
+Generated code targets the canonical `::agen` path and uses implementation dependencies re-exported by `agen`; consumers do not need direct `serde`, `schemars`, `serde_json`, or `async-trait` dependencies. Renaming the `agen` dependency in `Cargo.toml` is not currently supported.
+
+This companion package is published before the matching `agen` release. Its public contract is the generated API consumed by `agen`, and its minor version compatibility follows the `agen` 0.2 series.
+
+Licensed under the [MIT License](https://gitea.hareworks.net/Hare/yoi/src/branch/develop/LICENSE).