docs: refresh contributor architecture guidance

.github/ISSUE_TEMPLATE/feature_request.md

@@ -20,8 +20,9 @@ What else did you try or consider? Why is the proposal preferable?
 
 ## Scope notes
 
-- Is this a new role/component in the chain (RequestProcessor / LLMBackend / ResponseProcessor / ResponseTranslator), or an extension of an existing one?
-- Does it touch a public API listed in `switchyard/__init__.py.__all__`?
+- Which surface owns the change: server API or configuration, routing algorithm,
+  protocol type, translation codec, upstream client, Python binding, or launcher?
+- Does it change a public Rust, PyO3, Python, CLI, or deployment-TOML interface?
 - Backward-compatibility concerns?
 
 ## Additional context

CONTRIBUTING.md

@@ -73,6 +73,11 @@ uv run mypy switchyard
 
 # Tests — no failures
 uv run pytest tests/ -v
+
+# Rust formatting, linting, and tests
+cargo fmt --all --check
+cargo clippy --workspace --all-targets -- -D warnings
+cargo test --workspace
 ```
 
 These commands run in CI on every push. **Fix linting errors locally before pushing:**
@@ -130,6 +135,9 @@ feat(api)!: remove legacy route option
    uv run ruff check .
    uv run mypy switchyard
    uv run pytest tests/ -v
+   cargo fmt --all --check
+   cargo clippy --workspace --all-targets -- -D warnings
+   cargo test --workspace
    ```
 
 4. **Push and open a PR** on GitHub. Include:
@@ -152,6 +160,7 @@ workflows (commitlint, PR title) run on every PR but are advisory.
 
 ```bash
 uv run pytest tests/ -v
+cargo test --workspace
 ```
 
 ### Integration tests (requires API keys)
@@ -167,19 +176,29 @@ The default unit test suite runs with no network access and no API keys. Live, e
 
 ## Architecture
 
-See [Agents](AGENTS.md) for the full architecture guide. Key points:
+See [Architecture](docs/architecture.md) for the request lifecycle and
+[Agents](AGENTS.md) for crate boundaries and repository conventions. The
+supported serving path is native Rust:
+
+```text
+HTTP request → switchyard-server → libsy → libsy-llm-client
+             → switchyard-translation → upstream model
+```
 
-- **Typed requests/responses** — use `ChatRequest` and `ChatResponse` subtypes
-- **Composable chain** — `RequestProcessor` → `LLMBackend` → `ResponseProcessor` → `TranslationEngine`
-- **Profiles** — pre-built chains in `switchyard/lib/profiles/`
+Before making a change, identify the surface that owns it:
 
-When adding a new component:
+- Put routing algorithms and driver behavior in `crates/libsy`.
+- Put provider-neutral request and response types in `crates/protocol`.
+- Put translated HTTP calls in `crates/libsy-llm-client`.
+- Put wire-format conversion in `crates/switchyard-translation`.
+- Put HTTP serving and deployment configuration in `crates/switchyard-server`.
+- Put native Python bindings in `crates/switchyard-py`; keep Python wrappers in
+  `switchyard/libsy` or `switchyard_rust`.
+- Put launcher behavior in `switchyard/cli`.
 
-1. Decide the role: `RequestProcessor`, `LLMBackend`, `ResponseProcessor`, or translation engine work.
-2. Subclass the ABC from `switchyard/lib/roles.py`.
-3. Put Python middleware in the matching subpackage (`switchyard/lib/processors/`, `switchyard/lib/backends/`) and provider translation logic in `crates/switchyard-translation`.
-4. Add tests in `tests/`.
-5. Export from the relevant `__init__.py` and from `switchyard/__init__.py`'s `__all__`.
+Add Rust tests in the owning crate and Python tests in `tests/`. Export new
+public symbols from the owning crate or package rather than the top-level
+`switchyard` package unless that package owns the API.
 
 ## Documentation
 

DEVELOPMENT.md

@@ -5,7 +5,7 @@ Switchyard itself. If you only want to **use** the package, see
 [README](README.md).
 
 For deeper architectural docs, see [Agents](AGENTS.md) and
-[Architecture](docs/ARCHITECTURE.md).
+[Architecture](docs/architecture.md).
 
 ## Setup
 
@@ -40,30 +40,21 @@ uv sync --all-extras     # everything (dev group is still included by default)
 ## Project Structure
 
 ```
-switchyard/
-├── switchyard/                    # The package itself
-│   ├── __init__.py                # Public API exports (single source of truth)
-│   ├── lib/                       # Core library
-│   │   ├── roles.py               # RequestProcessor, LLMBackend, ResponseProcessor ABCs
-│   │   ├── switchyard.py          # Switchyard chain executor
-│   │   ├── profiles/              # Profile configs/runtimes (passthrough, random_routing, …)
-│   │   ├── proxy_context.py       # ProxyContext — per-request state
-│   │   ├── chat_request/          # Typed request hierarchy
-│   │   ├── chat_response/         # Typed response hierarchy
-│   │   ├── backends/              # LLMBackend implementations
-│   │   ├── processors/            # RequestProcessor / ResponseProcessor implementations
-│   │   ├── factories/             # MiddlewareFactory implementations + configs
-│   │   └── endpoints/             # FastAPI endpoint wrappers (require [server])
-│   ├── cli/                       # CLI entry point (requires [cli])
-│   └── server/                    # FastAPI app factory + verify helpers (requires [server])
-├── crates/
-│   ├── switchyard-translation/     # Rust request/response/stream translation engine
-│   └── switchyard-py/              # Thin PyO3 bindings plus Python convenience wrapper
-├── tests/                         # Pytest unit tests (no API keys required)
-├── examples/                      # Minimal usage examples
-├── docs/                          # Architecture, getting started, publication
-├── secrets/                       # Local credential template (git-ignored)
-└── pyproject.toml
+switchyard/                       # Python package
+├── cli/                          # CLI and coding-agent launchers
+└── libsy/                        # Typed wrappers for libsy algorithms
+switchyard_rust/                  # Python facades over the PyO3 extension
+crates/
+├── libsy/                         # Routing algorithms and driver
+├── libsy-llm-client/              # Translated HTTP model calls
+├── protocol/                      # Provider-neutral protocol types
+├── switchyard-py/                 # PyO3 bindings for libsy and the server
+├── switchyard-server/             # Native HTTP server and TOML configuration
+├── switchyard-skill-distillation/ # Skill-distillation contracts
+└── switchyard-translation/        # Request, response, and stream translation
+tests/                            # Python tests (no API keys required)
+docs/                             # User and architecture documentation
+pyproject.toml                    # Python package and development tooling
 ```
 
 ## Development Workflow
@@ -78,6 +69,11 @@ uv run pytest tests/ -v
 # Lint and type check
 uv run ruff check .
 uv run mypy switchyard
+
+# Rust formatting, linting, and tests
+cargo fmt --all --check
+cargo clippy --workspace --all-targets -- -D warnings
+cargo test --workspace
 ```
 
 > **Local Git hooks:** install both `pre-commit` and `commit-msg` hooks with