feat: add pre-commit and pre-push git hooks

Pre-commit runs go vet, golangci-lint (optional), and fast tests.
Pre-push runs full test suite and build verification.
Installable via `make hooks`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/hooks/pre-commit

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Pre-commit hook: fast quality checks on staged Go files
+set -e
+
+echo "🔍 Pre-commit checks..."
+
+# Check if any Go files are staged
+STAGED_GO_FILES=$(git diff --cached --name-only --diff-filter=ACM | grep '\.go$' || true)
+
+if [ -z "$STAGED_GO_FILES" ]; then
+    echo "✅ No Go files staged, skipping checks"
+    exit 0
+fi
+
+# 1. go vet
+echo "  Running go vet..."
+CGO_ENABLED=0 go vet ./... || { echo "❌ go vet failed"; exit 1; }
+
+# 2. golangci-lint (skip if not installed)
+if command -v golangci-lint &> /dev/null; then
+    echo "  Running golangci-lint..."
+    golangci-lint run --new-from-rev=HEAD~1 ./... || { echo "❌ golangci-lint failed"; exit 1; }
+else
+    echo "  ⚠️  golangci-lint not found, skipping (install: go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest)"
+fi
+
+# 3. Fast unit tests (short mode)
+echo "  Running fast tests..."
+CGO_ENABLED=0 go test -short -count=1 ./... || { echo "❌ tests failed"; exit 1; }
+
+echo "✅ All pre-commit checks passed"