chore: treat clippy warnings as errors in CI and document pre-push hook

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

Author: Lewis-E

.githooks/pre-push

@@ -5,15 +5,15 @@ echo ">>> [pre-push] Running cargo fmt --check..."
 if ! cargo fmt --all -- --check; then
     echo ""
     echo "HOOK FAILED: cargo fmt check failed."
-    echo "LLM FIX: run 'cargo fmt --all' then re-attempt the push."
+    echo "Try 'cargo fmt --all' then re-attempt the push."
     exit 1
 fi
 
 echo ">>> [pre-push] Running cargo clippy..."
 if ! cargo clippy --workspace --all-targets --all-features -- -D warnings; then
     echo ""
     echo "HOOK FAILED: cargo clippy reported warnings or errors."
-    echo "LLM FIX: fix the clippy diagnostics above, then re-attempt the push."
+    echo "Fix the clippy diagnostics above, then re-attempt the push."
     exit 1
 fi
 

.github/workflows/cargo.yml

@@ -60,7 +60,7 @@ jobs:
             # doesn't fail.
             export AWS_LC_FIPS_SYS_NO_ASM=1
           fi
-          cargo clippy --workspace --all-features
+          cargo clippy --workspace --all-features -- -D warnings
 
   build:
     name: Build

README.md

@@ -1,3 +1,11 @@
 # Serverless Components
 
-A collection of libraries and binaries used for instrumenting AWS Lambda Functions, Azure Functions, and Azure Spring Apps.
+A collection of libraries and binaries used for instrumenting AWS Lambda Functions, Azure Functions, and Azure Spring Apps.
+
+## Development
+
+Install the git pre-push hook (runs `cargo fmt --check` and `cargo clippy -D warnings` before each push):
+
+```sh
+git config core.hooksPath .githooks
+```