feat(scheme): mae-scheme R7RS-small runtime — Phase 13a-d complete

.githooks/pre-commit

@@ -10,9 +10,8 @@ if ! cargo fmt --check --quiet 2>/dev/null; then
     exit 1
 fi
 
-# 2. Clippy lint check
-# Exclude mae-gui (requires skia/clang) and mae-test-fixtures (generated).
-if ! cargo clippy --workspace --all-targets --exclude mae-gui --exclude mae-test-fixtures -- -D warnings >/dev/null 2>&1; then
+# 2. Clippy lint check (must match `make clippy` and CI)
+if ! cargo clippy --workspace --all-targets -- -D warnings >/dev/null 2>&1; then
     echo "❌ cargo clippy check failed. Run 'make clippy' to see errors."
     exit 1
 fi

.github/workflows/ci.yml

@@ -125,8 +125,6 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - name: Build binary
         run: cargo build --release --workspace
-      - name: Create Steel home directory
-        run: mkdir -p ~/.local/share/steel
       - name: Validate init.scm
         run: ./target/release/mae --check-config
       - name: Editor tests
@@ -144,13 +142,31 @@ jobs:
           ./target/release/mae --check-config
           test -f ~/.config/mae/packages.lock
 
+  scheme-runtime:
+    name: scheme / R7RS compliance
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: R7RS compliance tests
+        run: cargo test -p mae-scheme --test r7rs_compliance -- --nocapture
+        timeout-minutes: 10
+      - name: Scheme torture tests
+        run: cargo test -p mae-scheme --test scheme_torture -- --nocapture
+        timeout-minutes: 5
+      - name: Scheme benchmark tests
+        run: cargo test -p mae-scheme --test scheme_benchmarks -- --nocapture
+        timeout-minutes: 10
+      - name: Scheme real programs
+        run: cargo test -p mae-scheme --test scheme_programs -- --nocapture
+        timeout-minutes: 5
+      - name: Unit tests
+        run: cargo test -p mae-scheme --lib
+        timeout-minutes: 5
+
   collab-e2e:
     name: collab / docker e2e
-    # DISABLED: Docker E2E requires Scheme async/yield for reliable cross-container
-    # coordination. Protocol correctness is covered by collab_e2e.rs (28 tests),
-    # CRDT Scheme tests (142), and collab-local Scheme tests (85).
-    # Re-enable after Phase 13 Scheme runtime.
-    if: false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6

ARCHITECTURE.md

@@ -10,7 +10,7 @@ For user-facing docs, see README.md. For build instructions, see CLAUDE.md.
 | `mae-core` | Buffer (rope), event loop, editor state, commands, modes |
 | `mae-renderer` | TUI rendering via ratatui/crossterm (`Renderer` trait) |
 | `mae-gui` | GUI rendering via winit + Skia 2D |
-| `mae-scheme` | Embedded Steel Scheme runtime |
+| `mae-scheme` | Embedded R7RS-small Scheme runtime |
 | `mae-lsp` | LSP client (tower-lsp, diagnostics, completion) |
 | `mae-dap` | DAP client (breakpoints, step, inspect) |
 | `mae-ai` | AI agent transport (Claude/OpenAI/Gemini/DeepSeek) |

CLAUDE.md

@@ -35,7 +35,7 @@ The project README (`README.md`) contains the architecture spec and stack ration
 | `mae-core` | Buffer management (rope), event loop, core primitives | `ropey`, `crossbeam` |
 | `mae-renderer` | Display/rendering — `Renderer` trait + terminal backend | `ratatui`, `crossterm` |
 | `mae-gui` | GUI rendering backend — winit window + Skia 2D + native SVG | `winit`, `skia-safe` (features: `svg`) |
-| `mae-scheme` | Embedded Scheme runtime for configuration and packages | `steel` (or purpose-built) |
+| `mae-scheme` | Embedded Scheme runtime for configuration and packages | purpose-built R7RS-small |
 | `mae-lsp` | LSP client — types, references, diagnostics exposed to Scheme + AI | `tower-lsp` or `lsp-types` |
 | `mae-dap` | DAP client — breakpoints, call stacks, variables exposed to Scheme + AI | `dap-types` |
 | `mae-ai` | AI agent integration — tool-calling transport (Claude/OpenAI/Gemini/DeepSeek) | `reqwest`, `serde_json` |
@@ -104,7 +104,7 @@ Granular milestone tracking lives in **ROADMAP.md**.
 - Single-file editing with save/load
 
 ### Phase 2: Scheme Runtime — COMPLETE
-- Steel embedded as the extension language
+- mae-scheme R7RS-small runtime as the extension language
 - Buffer operations exposed to Scheme
 - Config file loading (`init.scm`)
 - Command binding from Scheme (`(define-key ...)`)
@@ -309,9 +309,8 @@ make test-scheme-all                # All local tests
 - **Rust-side iteration preferred.** Don't add `(run-tests)` at end of test files. The runner calls `run-nth-test` with `apply_to_editor` + `sync_scheme_state` between each step.
 
 ### Adding New Test Primitives
-- **Read-only state**: Add to `SharedState`, register `test-*` Rust function in `new()`, add Scheme forwarding in `install_mutable_buffer_accessors`, update in `sync_scheme_state`.
+- **Read-only state**: Add to `SharedState`, register Rust function in `new()` that reads from SharedState, update SharedState in `inject_editor_state`.
 - **Mutations**: Add pending field to `SharedState`, register Scheme function that sets it, process in `apply_to_editor`.
-- **Never call `inject_editor_state` between test registration and execution** — it shadows captured bindings (Steel `register_value` creates new cells).
 
 ## Developing MAE Inside MAE (MCP Tools)
 
@@ -510,7 +509,6 @@ These APIs are intended to remain stable through v1.0:
 - **Full architecture spec:** `README.md`
 - **Emacs source for reference:** the Emacs source tree (clone of emacs-mirror/emacs, `emacs-30` branch)
 - **Declarative project config:** `.project` in repo root (for declarative-project-mode in Emacs)
-- **Steel Scheme:** https://github.com/mattwparas/steel — primary candidate for embedded Scheme runtime
 - **ropey:** https://github.com/cessen/ropey — rope data structure for buffer management
 - **ratatui:** https://github.com/ratatui/ratatui — terminal UI framework
 - **tree-sitter-org:** org-mode grammar for tree-sitter

CONTRIBUTING.md

@@ -49,7 +49,7 @@ MAE is split into 10 crates (see `README.md` for the full layout):
 | `mae-core` | Buffer (rope), editor state, commands, keymap, syntax, babel, export |
 | `mae-renderer` | Terminal rendering (ratatui), status bar, popups |
 | `mae-gui` | GUI rendering (winit + Skia 2D), mouse, fonts, inline images |
-| `mae-scheme` | Steel Scheme runtime, init.scm loading, hook dispatch |
+| `mae-scheme` | R7RS-small Scheme runtime, init.scm loading, hook dispatch |
 | `mae-ai` | AI providers (Claude/OpenAI/Gemini/DeepSeek), tool execution |
 | `mae-lsp` | LSP client — connection, navigation, diagnostics, completion |
 | `mae-dap` | DAP client — breakpoints, stepping, watches |