rename AGENT.md to AGENTS.md

AGENTS.md

@@ -18,7 +18,23 @@ cargo clippy --workspace --all-targets -- -D warnings   # must stay clean
 cargo fmt --all
 ```
 
+The server build runs `build.rs`, which builds `ui/` for `wasm32-unknown-unknown`
+and embeds the generated assets; there is no separate UI packaging step. See
+[README.md](README.md) for setup and run instructions.
+
+## Project Context
+
+- `src/main.rs` hosts the Axum API and simulation thread; `src/world.rs` owns
+  world behavior and snapshots; `src/storage.rs` persists snapshots.
+- `config.rn` defines the Rune simulation defaults and agent behavior. Runtime
+  script edits are not written back to this file; see the README before changing
+  reset or persistence behavior.
+- `ui/` is the Leptos/Wasm frontend. Keep its API/model changes aligned with the
+  server payloads in `src/main.rs`.
+
 ## Conventions
 
 - Comment only code that needs clarification.
 - Warnings are treated as errors (`-D warnings`).
+- After Rust changes, run `cargo fmt --all`; formatting is not needed for
+  documentation-only changes.

CLAUDE.md

@@ -0,0 +1 @@
+AGENTS.md