Add critical instructions and hooks for Claude Code

.claude/settings.json

@@ -0,0 +1,15 @@
+{
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": "Edit|Write",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "echo '\n[Reminder] Run: cargo fmt --all && make lint-fix && cargo check'"
+          }
+        ]
+      }
+    ]
+  }
+}

CLAUDE.md

@@ -2,6 +2,12 @@
 
 This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
 
+## CRITICAL - Always Follow
+
+After completing ANY code changes:
+1. **MUST** run `cargo fmt --all && make lint-fix` to format and fix linting issues
+2. **MUST** run `cargo check` to verify compilation before considering task complete
+
 ## Development Commands
 
 **Important**: Always branch from `unstable` and target `unstable` when creating pull requests.

Cargo.toml

@@ -120,6 +120,7 @@ bytes = "1.11.1"
 # Turn off c-kzg's default features which include `blst/portable`. We can turn on blst's portable
 # feature ourselves when desired.
 c-kzg = { version = "2.1", default-features = false }
+cargo-husky = { version = "1", default-features = false, features = ["precommit-hook", "run-cargo-fmt"] }
 cargo_metadata = "0.19"
 clap = { version = "4.5.4", features = ["derive", "cargo", "wrap_help"] }
 clap_utils = { path = "common/clap_utils" }

lighthouse/Cargo.toml

@@ -10,6 +10,7 @@ rust-version = "1.88.0"
 # to assert properties of the compilation target.
 [package.metadata.cargo-udeps.ignore]
 normal = ["target_check"]
+development = ["cargo-husky"]
 
 [features]
 default = ["slasher-lmdb", "beacon-node-leveldb"]
@@ -84,6 +85,7 @@ malloc_utils = { workspace = true, features = [] }
 beacon_node = { workspace = true, features = ["testing"] }
 beacon_node_fallback = { workspace = true }
 beacon_processor = { workspace = true }
+cargo-husky = { workspace = true }
 eth2 = { workspace = true }
 initialized_validators = { workspace = true }
 lighthouse_network = { workspace = true }