feat: add release build script for multi-platform binaries

- Add scripts/release.sh for automated release builds
- Creates tar.gz packages for Linux and macOS
- Generates SHA256 checksums
- Add 'make release' target
- Add releases/ to .gitignore

Usage:
  make release  # Build and package for all platforms

Output: releases/v0.2.5/*.tar.gz + SHA256SUMS.txt

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

scripts/release.sh

@@ -0,0 +1,92 @@
+#!/bin/bash
+set -e
+
+# QuoteForge Release Build Script
+# Creates binaries for all platforms and packages them for release
+
+# Colors
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Get version from git
+VERSION=$(git describe --tags --always --dirty 2>/dev/null || echo "dev")
+if [[ $VERSION == *"dirty"* ]]; then
+    echo -e "${RED}✗ Error: Working directory has uncommitted changes${NC}"
+    echo "  Commit your changes first"
+    exit 1
+fi
+
+echo -e "${GREEN}Building QuoteForge version: ${VERSION}${NC}"
+echo ""
+
+# Create release directory
+RELEASE_DIR="releases/${VERSION}"
+mkdir -p "${RELEASE_DIR}"
+
+# Build for all platforms
+echo -e "${YELLOW}→ Building binaries...${NC}"
+make build-all
+
+# Package binaries with checksums
+echo ""
+echo -e "${YELLOW}→ Creating release packages...${NC}"
+
+# Linux AMD64
+if [ -f "bin/qfs-linux-amd64" ]; then
+    cd bin
+    tar -czf "../${RELEASE_DIR}/qfs-${VERSION}-linux-amd64.tar.gz" qfs-linux-amd64
+    cd ..
+    echo -e "${GREEN}  ✓ qfs-${VERSION}-linux-amd64.tar.gz${NC}"
+fi
+
+# macOS Intel
+if [ -f "bin/qfs-darwin-amd64" ]; then
+    cd bin
+    tar -czf "../${RELEASE_DIR}/qfs-${VERSION}-darwin-amd64.tar.gz" qfs-darwin-amd64
+    cd ..
+    echo -e "${GREEN}  ✓ qfs-${VERSION}-darwin-amd64.tar.gz${NC}"
+fi
+
+# macOS Apple Silicon
+if [ -f "bin/qfs-darwin-arm64" ]; then
+    cd bin
+    tar -czf "../${RELEASE_DIR}/qfs-${VERSION}-darwin-arm64.tar.gz" qfs-darwin-arm64
+    cd ..
+    echo -e "${GREEN}  ✓ qfs-${VERSION}-darwin-arm64.tar.gz${NC}"
+fi
+
+# Generate checksums
+echo ""
+echo -e "${YELLOW}→ Generating checksums...${NC}"
+cd "${RELEASE_DIR}"
+shasum -a 256 *.tar.gz > SHA256SUMS.txt
+cd ../..
+echo -e "${GREEN}  ✓ SHA256SUMS.txt${NC}"
+
+# List release files
+echo ""
+echo -e "${GREEN}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
+echo -e "${GREEN}Release ${VERSION} built successfully!${NC}"
+echo -e "${GREEN}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
+echo ""
+echo "Files in ${RELEASE_DIR}:"
+ls -lh "${RELEASE_DIR}"
+echo ""
+
+# Show next steps
+echo -e "${YELLOW}Next steps:${NC}"
+echo "  1. Create git tag:"
+echo "     git tag -a ${VERSION} -m \"Release ${VERSION}\""
+echo ""
+echo "  2. Push tag to remote:"
+echo "     git push origin ${VERSION}"
+echo ""
+echo "  3. Create release on git.mchus.pro:"
+echo "     - Go to: https://git.mchus.pro/mchus/QuoteForge/releases"
+echo "     - Click 'New Release'"
+echo "     - Select tag: ${VERSION}"
+echo "     - Upload files from: ${RELEASE_DIR}/"
+echo ""
+echo -e "${GREEN}Done!${NC}"