diff --git a/checkpoint.json b/checkpoint.json
new file mode 100644
index 000000000..7e81c01d4
--- /dev/null
+++ b/checkpoint.json
@@ -0,0 +1,52 @@
+{
+  "timestamp": "2026-03-15T16:57:35.652960Z",
+  "current_node": "toolchain",
+  "completed_nodes": [
+    "start",
+    "toolchain"
+  ],
+  "node_retries": {
+    "toolchain": 1,
+    "start": 1
+  },
+  "context_values": {
+    "graph.model_stylesheet": "\n            * { backend: api; model: claude-opus-4-6;}\n        ",
+    "current.preamble": "Goal: # Plan: Add `prevent_idle_sleep` to fabro via `fabro-beastie`\n\n## Context\n\nLong-running `fabro run` and `fabro exec` commands can be killed by OS idle sleep. We want a compile-time Cargo feature `sleep_inhibitor` on `fabro-cli` (disabled by default) that, when compiled in, reads a `prevent_idle_sleep` flag from `cli.toml` to prevent idle system sleep while fabro is working. Named after Beastie Boys — No Sleep Till Brooklyn.\n\n## TDD Approach\n\nRed-green for each step: write a failing test first, then make it pass, then move to the next piece.\n\n## Steps\n\n### Step 1: Create `lib/crates/fabro-beastie/` crate\n\n#### 1a. Dummy backend + public API (red-green)\n\nCreate crate with `Cargo.toml`, `src/lib.rs`, `src/dummy.rs`.\n\n**Test first (red):** unit test that `guard(true)` returns `Some` and `guard(false)` returns `None`.\n\n**`Cargo.toml`:**\n```toml\n[package]\nname = \"fabro-beastie\"\nedition.workspace = true\nversion.workspace = true\nlicense.workspace = true\ndescription = \"Cross-platform idle sleep prevention (No Sleep Till Brooklyn)\"\n\n[lib]\ndoctest = false\n\n[dependencies]\ntracing.workspace = true\n\n[target.'cfg(target_os = \"macos\")'.dependencies]\ncore-foundation = \"0.9\"\n\n[target.'cfg(target_os = \"linux\")'.dependencies]\nlibc.workspace = true\n```\n\n**Public API (`src/lib.rs`):**\n```rust\npub fn guard(enabled: bool) -> Option<SleepInhibitorGuard> { ... }\n```\n`SleepInhibitorGuard` acquires on creation, releases on `Drop`.\n\nPlatform dispatch via `cfg(target_os)` to `macos`, `linux`, or `dummy` modules.\n\n**Green:** implement with dummy backend first so tests pass on all platforms.\n\nAdd to workspace `Cargo.toml` members list.\n\n#### 1b. macOS backend (red-green)\n\nCreate `src/macos.rs` + `src/iokit_bindings.rs`.\n\n**Test (red):** `guard(true)` returns `Some`, drop doesn't panic. (Same logical test as 1a, but now exercises real IOKit path on macOS.)\n\n**Green:** IOKit `IOPMAssertionCreateWithName(\"PreventUserIdleSystemSleep\")` on acquire, `IOPMAssertionRelease` on drop. Idempotent acquire (early return if already held). Warn on failure, don't panic.\n\n#### 1c. Linux backend (red-green)\n\nCreate `src/linux.rs`.\n\n**Test (red):** same pattern — create guard, drop without panic.\n\n**Green:** Spawn `systemd-inhibit --what=idle --mode=block` (fallback `gnome-session-inhibit`). Kill child on drop. Use `PR_SET_PDEATHSIG` for safety.\n\n### Step 2: Config — add `prevent_idle_sleep` to `CliConfig`\n\n**File:** `lib/crates/fabro-config/src/cli.rs`\n\n**Test (red):** parse `prevent_idle_sleep = true` from TOML, assert field is `true`. Parse empty TOML, assert field is `false`.\n\n**Green:** Add `#[serde(default)] pub prevent_idle_sleep: bool` to `CliConfig`.\n\n### Step 3: Wire into `fabro-cli` behind `sleep_inhibitor` feature\n\n**Files:**\n- `lib/crates/fabro-cli/Cargo.toml` — add feature `sleep_inhibitor = [\"dep:fabro-beastie\"]` and optional dep\n- `lib/crates/fabro-cli/src/main.rs` — guard both `fabro run` and `fabro exec` paths\n\n**`fabro exec` path (~line 437-496):**\n```rust\n#[cfg(feature = \"sleep_inhibitor\")]\nlet _sleep_guard = fabro_beastie::guard(cli_config.prevent_idle_sleep);\n```\nPlace before the `run_with_args` / `run_with_args_and_client` calls.\n\n**`fabro run` path (~line 498-517):**\nPass `cli_config.prevent_idle_sleep` to `run_command`. Inside `run_command` (~line 1184):\n```rust\n#[cfg(feature = \"sleep_inhibitor\")]\nlet _sleep_guard = fabro_beastie::guard(prevent_idle_sleep);\n```\n\nFor the `run` path, `fabro-workflows` also needs the optional dep:\n- `lib/crates/fabro-workflows/Cargo.toml` — add `sleep_inhibitor = [\"dep:fabro-beastie\"]` feature + optional dep\n- `lib/crates/fabro-cli/Cargo.toml` — update `sleep_inhibitor` feature to forward: `sleep_inhibitor = [\"dep:fabro-beastie\", \"fabro-workflows/sleep_inhibitor\"]`\n\n## Files to create/modify\n\n| File | Action |\n|------|--------|\n| `lib/crates/fabro-beastie/Cargo.toml` | Create |\n| `lib/crates/fabro-beastie/src/lib.rs` | Create |\n| `lib/crates/fabro-beastie/src/macos.rs` | Create |\n| `lib/crates/fabro-beastie/src/iokit_bindings.rs` | Create |\n| `lib/crates/fabro-beastie/src/linux.rs` | Create |\n| `lib/crates/fabro-beastie/src/dummy.rs` | Create |\n| `Cargo.toml` (workspace root) | Add member |\n| `lib/crates/fabro-config/src/cli.rs` | Add field + test |\n| `lib/crates/fabro-cli/Cargo.toml` | Add feature + optional dep |\n| `lib/crates/fabro-cli/src/main.rs` | `cfg`-guarded guards for exec |\n| `lib/crates/fabro-workflows/Cargo.toml` | Add feature + optional dep |\n| `lib/crates/fabro-workflows/src/cli/run.rs` | Accept flag, `cfg`-guarded guard |\n\n## Verification\n\n1. `cargo test -p fabro-beastie` — unit tests pass\n2. `cargo test -p fabro-config` — config parsing tests pass\n3. `cargo build --workspace` — compiles without the feature (no fabro-beastie pulled in)\n4. `cargo build --workspace --features fabro-cli/sleep_inhibitor` — compiles with the feature\n5. `cargo clippy --workspace -- -D warnings` + `cargo fmt --check --all`\n6. Manual: enable feature, set `prevent_idle_sleep = true` in `~/.fabro/cli.toml`, run `fabro exec`, confirm machine stays awake\n\n",
+    "outcome": "success",
+    "internal.retry_count.toolchain": 1,
+    "command.stderr": "",
+    "thread.start.current_node": "toolchain",
+    "internal.run_id": "01KKS6WW07GQBH57MN79B016ST",
+    "internal.node_visit_count": 1,
+    "graph.goal": "# Plan: Add `prevent_idle_sleep` to fabro via `fabro-beastie`\n\n## Context\n\nLong-running `fabro run` and `fabro exec` commands can be killed by OS idle sleep. We want a compile-time Cargo feature `sleep_inhibitor` on `fabro-cli` (disabled by default) that, when compiled in, reads a `prevent_idle_sleep` flag from `cli.toml` to prevent idle system sleep while fabro is working. Named after Beastie Boys — No Sleep Till Brooklyn.\n\n## TDD Approach\n\nRed-green for each step: write a failing test first, then make it pass, then move to the next piece.\n\n## Steps\n\n### Step 1: Create `lib/crates/fabro-beastie/` crate\n\n#### 1a. Dummy backend + public API (red-green)\n\nCreate crate with `Cargo.toml`, `src/lib.rs`, `src/dummy.rs`.\n\n**Test first (red):** unit test that `guard(true)` returns `Some` and `guard(false)` returns `None`.\n\n**`Cargo.toml`:**\n```toml\n[package]\nname = \"fabro-beastie\"\nedition.workspace = true\nversion.workspace = true\nlicense.workspace = true\ndescription = \"Cross-platform idle sleep prevention (No Sleep Till Brooklyn)\"\n\n[lib]\ndoctest = false\n\n[dependencies]\ntracing.workspace = true\n\n[target.'cfg(target_os = \"macos\")'.dependencies]\ncore-foundation = \"0.9\"\n\n[target.'cfg(target_os = \"linux\")'.dependencies]\nlibc.workspace = true\n```\n\n**Public API (`src/lib.rs`):**\n```rust\npub fn guard(enabled: bool) -> Option<SleepInhibitorGuard> { ... }\n```\n`SleepInhibitorGuard` acquires on creation, releases on `Drop`.\n\nPlatform dispatch via `cfg(target_os)` to `macos`, `linux`, or `dummy` modules.\n\n**Green:** implement with dummy backend first so tests pass on all platforms.\n\nAdd to workspace `Cargo.toml` members list.\n\n#### 1b. macOS backend (red-green)\n\nCreate `src/macos.rs` + `src/iokit_bindings.rs`.\n\n**Test (red):** `guard(true)` returns `Some`, drop doesn't panic. (Same logical test as 1a, but now exercises real IOKit path on macOS.)\n\n**Green:** IOKit `IOPMAssertionCreateWithName(\"PreventUserIdleSystemSleep\")` on acquire, `IOPMAssertionRelease` on drop. Idempotent acquire (early return if already held). Warn on failure, don't panic.\n\n#### 1c. Linux backend (red-green)\n\nCreate `src/linux.rs`.\n\n**Test (red):** same pattern — create guard, drop without panic.\n\n**Green:** Spawn `systemd-inhibit --what=idle --mode=block` (fallback `gnome-session-inhibit`). Kill child on drop. Use `PR_SET_PDEATHSIG` for safety.\n\n### Step 2: Config — add `prevent_idle_sleep` to `CliConfig`\n\n**File:** `lib/crates/fabro-config/src/cli.rs`\n\n**Test (red):** parse `prevent_idle_sleep = true` from TOML, assert field is `true`. Parse empty TOML, assert field is `false`.\n\n**Green:** Add `#[serde(default)] pub prevent_idle_sleep: bool` to `CliConfig`.\n\n### Step 3: Wire into `fabro-cli` behind `sleep_inhibitor` feature\n\n**Files:**\n- `lib/crates/fabro-cli/Cargo.toml` — add feature `sleep_inhibitor = [\"dep:fabro-beastie\"]` and optional dep\n- `lib/crates/fabro-cli/src/main.rs` — guard both `fabro run` and `fabro exec` paths\n\n**`fabro exec` path (~line 437-496):**\n```rust\n#[cfg(feature = \"sleep_inhibitor\")]\nlet _sleep_guard = fabro_beastie::guard(cli_config.prevent_idle_sleep);\n```\nPlace before the `run_with_args` / `run_with_args_and_client` calls.\n\n**`fabro run` path (~line 498-517):**\nPass `cli_config.prevent_idle_sleep` to `run_command`. Inside `run_command` (~line 1184):\n```rust\n#[cfg(feature = \"sleep_inhibitor\")]\nlet _sleep_guard = fabro_beastie::guard(prevent_idle_sleep);\n```\n\nFor the `run` path, `fabro-workflows` also needs the optional dep:\n- `lib/crates/fabro-workflows/Cargo.toml` — add `sleep_inhibitor = [\"dep:fabro-beastie\"]` feature + optional dep\n- `lib/crates/fabro-cli/Cargo.toml` — update `sleep_inhibitor` feature to forward: `sleep_inhibitor = [\"dep:fabro-beastie\", \"fabro-workflows/sleep_inhibitor\"]`\n\n## Files to create/modify\n\n| File | Action |\n|------|--------|\n| `lib/crates/fabro-beastie/Cargo.toml` | Create |\n| `lib/crates/fabro-beastie/src/lib.rs` | Create |\n| `lib/crates/fabro-beastie/src/macos.rs` | Create |\n| `lib/crates/fabro-beastie/src/iokit_bindings.rs` | Create |\n| `lib/crates/fabro-beastie/src/linux.rs` | Create |\n| `lib/crates/fabro-beastie/src/dummy.rs` | Create |\n| `Cargo.toml` (workspace root) | Add member |\n| `lib/crates/fabro-config/src/cli.rs` | Add field + test |\n| `lib/crates/fabro-cli/Cargo.toml` | Add feature + optional dep |\n| `lib/crates/fabro-cli/src/main.rs` | `cfg`-guarded guards for exec |\n| `lib/crates/fabro-workflows/Cargo.toml` | Add feature + optional dep |\n| `lib/crates/fabro-workflows/src/cli/run.rs` | Accept flag, `cfg`-guarded guard |\n\n## Verification\n\n1. `cargo test -p fabro-beastie` — unit tests pass\n2. `cargo test -p fabro-config` — config parsing tests pass\n3. `cargo build --workspace` — compiles without the feature (no fabro-beastie pulled in)\n4. `cargo build --workspace --features fabro-cli/sleep_inhibitor` — compiles with the feature\n5. `cargo clippy --workspace -- -D warnings` + `cargo fmt --check --all`\n6. Manual: enable feature, set `prevent_idle_sleep = true` in `~/.fabro/cli.toml`, run `fabro exec`, confirm machine stays awake\n",
+    "internal.thread_id": "start",
+    "failure_signature": "",
+    "command.output": "cargo 1.94.0 (85eff7c80 2026-01-15)\n",
+    "graph.rankdir": "LR",
+    "internal.fidelity": "compact",
+    "failure_class": "",
+    "current_node": "toolchain",
+    "internal.retry_count.start": 1
+  },
+  "logs": [],
+  "node_outcomes": {
+    "start": {
+      "status": "success",
+      "duration_ms": 0
+    },
+    "toolchain": {
+      "status": "success",
+      "context_updates": {
+        "command.stderr": "",
+        "command.output": "cargo 1.94.0 (85eff7c80 2026-01-15)\n"
+      },
+      "notes": "Script completed: command -v cargo >/dev/null || { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && sudo ln -sf $HOME/.cargo/bin/* /usr/local/bin/; }; cargo --version 2>&1",
+      "duration_ms": 63
+    }
+  },
+  "next_node_id": "preflight_compile",
+  "node_visits": {
+    "toolchain": 1,
+    "start": 1
+  }
+}
\ No newline at end of file
diff --git a/nodes/start/status.json b/nodes/start/status.json
new file mode 100644
index 000000000..9ad2d362c
--- /dev/null
+++ b/nodes/start/status.json
@@ -0,0 +1,6 @@
+{
+  "status": "success",
+  "notes": null,
+  "failure_reason": null,
+  "timestamp": "2026-03-15T16:57:35.571218+00:00"
+}
\ No newline at end of file
diff --git a/nodes/toolchain/script_invocation.json b/nodes/toolchain/script_invocation.json
new file mode 100644
index 000000000..d68c414c4
--- /dev/null
+++ b/nodes/toolchain/script_invocation.json
@@ -0,0 +1,5 @@
+{
+  "command": "command -v cargo >/dev/null || { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && sudo ln -sf $HOME/.cargo/bin/* /usr/local/bin/; }; cargo --version 2>&1",
+  "language": "shell",
+  "timeout_ms": null
+}
\ No newline at end of file
diff --git a/nodes/toolchain/script_timing.json b/nodes/toolchain/script_timing.json
new file mode 100644
index 000000000..7e6b5b86a
--- /dev/null
+++ b/nodes/toolchain/script_timing.json
@@ -0,0 +1,5 @@
+{
+  "duration_ms": 62,
+  "exit_code": 0,
+  "timed_out": false
+}
\ No newline at end of file
diff --git a/nodes/toolchain/status.json b/nodes/toolchain/status.json
new file mode 100644
index 000000000..8d9333e67
--- /dev/null
+++ b/nodes/toolchain/status.json
@@ -0,0 +1,6 @@
+{
+  "status": "success",
+  "notes": "Script completed: command -v cargo >/dev/null || { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && sudo ln -sf $HOME/.cargo/bin/* /usr/local/bin/; }; cargo --version 2>&1",
+  "failure_reason": null,
+  "timestamp": "2026-03-15T16:57:35.652607+00:00"
+}
\ No newline at end of file