feat: add target repo examples and file layout guidance

examples/rust-project/AGENTS.md

@@ -0,0 +1,25 @@
+# AGENTS.md
+
+## Project overview
+This repository is a Rust service or CLI with one or more crates.
+
+## Important directories
+- `src/` — primary crate source
+- `crates/` — workspace member crates if present
+- `tests/` — integration tests
+- `benches/` — benchmarks if present
+
+## Commands
+- test: `cargo test`
+- build: `cargo build`
+- lint: `cargo clippy --all-targets --all-features -- -D warnings`
+- format check: `cargo fmt --check`
+
+## Working rules
+- Prefer minimal diffs
+- Do not casually update `Cargo.lock`
+- Avoid changing workspace structure unless explicitly requested
+- Add or update tests for behavior changes
+
+## Additional harness files
+See `ai/project-map.md`, `ai/task-templates.md`, and `ai/risk-guardrails.md`.