diff --git a/build.sh b/build.sh
new file mode 100644
index 0000000..a37572c
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,222 @@
+#!/usr/bin/env bash
+# =============================================================================
+# felhom-controller — Docker image build script
+# =============================================================================
+# Location: /home/kisfenyo/build/felhom-controller/build.sh
+#
+# Copies source from the git repo, syncs app assets, and builds the image.
+# Build artifacts stay here — the git repo stays clean.
+#
+# Usage:
+#   ./build.sh                    # Build for current platform, tag as :dev
+#   ./build.sh 0.1.0              # Build with version tag
+#   ./build.sh 0.1.0 --push       # Build + push to Gitea registry
+#   ./build.sh 0.1.0 --multiarch  # Build amd64+arm64 + push
+# =============================================================================
+set -euo pipefail
+
+# --- Configuration (edit these if your paths differ) ---
+REPO_DIR="/home/kisfenyo/git/deploy-felhom-compose"
+CONTROLLER_SRC="${REPO_DIR}/controller"
+WEBSITE_ASSETS_DIR="/home/kisfenyo/git/felhom.eu/website/assets"
+REGISTRY="gitea.dooplex.hu/admin"
+IMAGE="${REGISTRY}/felhom-controller"
+
+# Build workspace — a temp directory next to this script, NOT in the git repo
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+BUILD_DIR="${SCRIPT_DIR}/workspace"
+
+# --- Parse arguments ---
+VERSION="${1:-dev}"
+ACTION="${2:-}"  # --push or --multiarch
+
+# --- Colors ---
+RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; CYAN='\033[0;36m'; NC='\033[0m'
+info()  { echo -e "${GREEN}[INFO]${NC}  $*"; }
+warn()  { echo -e "${YELLOW}[WARN]${NC}  $*"; }
+error() { echo -e "${RED}[ERROR]${NC} $*"; }
+step()  { echo -e "${CYAN}[STEP]${NC}  $*"; }
+
+# --- Pre-flight checks ---
+if [[ ! -d "${CONTROLLER_SRC}" ]]; then
+    error "Controller source not found: ${CONTROLLER_SRC}"
+    error "Clone the repo first: git clone https://gitea.dooplex.hu/admin/deploy-felhom-compose.git ${REPO_DIR}"
+    exit 1
+fi
+
+if ! command -v docker &>/dev/null; then
+    error "Docker not found."
+    exit 1
+fi
+
+# Git metadata from the repo
+GIT_COMMIT="unknown"
+if [[ -d "${REPO_DIR}/.git" ]]; then
+    GIT_COMMIT=$(cd "${REPO_DIR}" && git rev-parse --short HEAD 2>/dev/null || echo "unknown")
+fi
+
+echo ""
+info "╔══════════════════════════════════════╗"
+info "║  felhom-controller image builder     ║"
+info "╚══════════════════════════════════════╝"
+info "Version:    ${VERSION}"
+info "Commit:     ${GIT_COMMIT}"
+info "Source:     ${CONTROLLER_SRC}"
+info "Build dir:  ${BUILD_DIR}"
+info "Image:      ${IMAGE}:${VERSION}"
+echo ""
+
+# =========================================================================
+# Step 1: Prepare clean build workspace
+# =========================================================================
+step "1/4 — Preparing build workspace..."
+
+rm -rf "${BUILD_DIR}"
+mkdir -p "${BUILD_DIR}"
+
+# Copy the entire controller directory (preserving subdirectory structure)
+cp -a "${CONTROLLER_SRC}/." "${BUILD_DIR}/"
+
+# Verify the expected Go package structure exists
+MISSING=()
+for required in cmd/controller/main.go internal/config/config.go internal/stacks/manager.go internal/api/router.go internal/web/server.go; do
+    if [[ ! -f "${BUILD_DIR}/${required}" ]]; then
+        MISSING+=("${required}")
+    fi
+done
+
+if [[ ${#MISSING[@]} -gt 0 ]]; then
+    error "Directory structure check FAILED. Missing files:"
+    for f in "${MISSING[@]}"; do
+        error "  ✗ ${f}"
+    done
+    error ""
+    error "The Go source must be in package subdirectories, not flat."
+    error "Run the restructure script first:"
+    error "  cd ${CONTROLLER_SRC} && bash restructure.sh"
+    error "  git add -A && git commit -m 'Restructure into Go package dirs'"
+    rm -rf "${BUILD_DIR}"
+    exit 1
+fi
+
+GO_COUNT=$(find "${BUILD_DIR}" -name '*.go' | wc -l)
+info "Source copied: ${GO_COUNT} Go files"
+
+# =========================================================================
+# Step 2: Sync app assets (logos + screenshots)
+# =========================================================================
+step "2/4 — Syncing app assets..."
+
+mkdir -p "${BUILD_DIR}/assets"
+
+if [[ -d "${WEBSITE_ASSETS_DIR}" ]]; then
+    # Count before copy
+    SVG_N=$(find "${WEBSITE_ASSETS_DIR}" -maxdepth 1 -name '*-logo.svg' 2>/dev/null | wc -l)
+    PNG_N=$(find "${WEBSITE_ASSETS_DIR}" -maxdepth 1 -name '*-logo.png' 2>/dev/null | wc -l)
+    SS_N=$(find "${WEBSITE_ASSETS_DIR}" -maxdepth 1 -name '*-screenshot-*.webp' 2>/dev/null | wc -l)
+
+    cp "${WEBSITE_ASSETS_DIR}"/*-logo.svg "${BUILD_DIR}/assets/" 2>/dev/null || true
+    cp "${WEBSITE_ASSETS_DIR}"/*-logo.png "${BUILD_DIR}/assets/" 2>/dev/null || true
+    cp "${WEBSITE_ASSETS_DIR}"/*-screenshot-*.webp "${BUILD_DIR}/assets/" 2>/dev/null || true
+
+    TOTAL=$(find "${BUILD_DIR}/assets" -type f ! -name 'README.md' 2>/dev/null | wc -l)
+    info "Synced ${TOTAL} assets (${SVG_N} SVG + ${PNG_N} PNG logos, ${SS_N} screenshots)"
+else
+    warn "Website assets not found: ${WEBSITE_ASSETS_DIR}"
+    warn "Building without logos/screenshots. Set WEBSITE_ASSETS_DIR if needed."
+fi
+
+# =========================================================================
+# Step 3: Run go mod tidy (to generate go.sum if missing)
+# =========================================================================
+step "3/4 — Preparing Go modules..."
+
+cd "${BUILD_DIR}"
+
+# The Dockerfile handles go mod download internally, but verify go.mod exists
+if [[ ! -f "go.mod" ]]; then
+    error "go.mod not found in build workspace!"
+    exit 1
+fi
+
+# If go is installed locally, run tidy to catch issues early
+if command -v go &>/dev/null; then
+    info "Running go mod tidy..."
+    go mod tidy 2>&1 || warn "go mod tidy had issues (Docker build may still work)"
+else
+    info "Go not installed locally — Docker build stage will handle dependencies."
+fi
+
+# =========================================================================
+# Step 4: Docker build
+# =========================================================================
+step "4/4 — Building Docker image..."
+
+BUILD_ARGS=(
+    --build-arg "VERSION=${VERSION}"
+    --build-arg "GIT_COMMIT=${GIT_COMMIT}"
+)
+
+case "${ACTION}" in
+    --push)
+        info "Building for current platform + pushing..."
+        docker build "${BUILD_ARGS[@]}" \
+            -t "${IMAGE}:${VERSION}" \
+            -t "${IMAGE}:latest" \
+            .
+
+        info "Pushing..."
+        docker push "${IMAGE}:${VERSION}"
+        docker push "${IMAGE}:latest"
+        ;;
+
+    --multiarch)
+        info "Building multi-arch (amd64 + arm64) + pushing..."
+
+        # Ensure buildx builder exists
+        if ! docker buildx inspect felhom-builder &>/dev/null; then
+            info "Creating buildx builder (one-time setup)..."
+            docker buildx create --name felhom-builder --use --bootstrap
+        else
+            docker buildx use felhom-builder
+        fi
+
+        docker buildx build "${BUILD_ARGS[@]}" \
+            --platform linux/amd64,linux/arm64 \
+            -t "${IMAGE}:${VERSION}" \
+            -t "${IMAGE}:latest" \
+            --push \
+            .
+        ;;
+
+    *)
+        info "Building for current platform (local only)..."
+        docker build "${BUILD_ARGS[@]}" \
+            -t "${IMAGE}:${VERSION}" \
+            -t "${IMAGE}:latest" \
+            .
+        ;;
+esac
+
+# =========================================================================
+# Summary
+# =========================================================================
+echo ""
+info "╔══════════════════════════════════════╗"
+info "║  Build complete ✓                    ║"
+info "╚══════════════════════════════════════╝"
+info "Image: ${IMAGE}:${VERSION}"
+
+# Show image size if available locally
+SIZE=$(docker image inspect "${IMAGE}:${VERSION}" --format='{{.Size}}' 2>/dev/null || echo "")
+if [[ -n "${SIZE}" ]]; then
+    SIZE_HUMAN=$(numfmt --to=iec "${SIZE}" 2>/dev/null || echo "${SIZE} bytes")
+    info "Size:  ${SIZE_HUMAN}"
+fi
+
+echo ""
+if [[ "${ACTION}" == "" ]]; then
+    info "Image is local only. To push:"
+    info "  ./build.sh ${VERSION} --push        # current arch"
+    info "  ./build.sh ${VERSION} --multiarch   # amd64 + arm64"
+fi
\ No newline at end of file
diff --git a/collect-repos.sh b/collect-repos.sh
index e4fadad..7111522 100644
--- a/collect-repos.sh
+++ b/collect-repos.sh
@@ -2,6 +2,7 @@
 # collect-repos.sh
 # Run from ~/git/ - combines all files from each repo into a single .txt file
 # Output goes to ~/git/collected/ folder
+# Output files are UTF-8 with BOM for maximum compatibility
 
 set -euo pipefail
 
@@ -47,7 +48,7 @@ should_skip_file() {
 }
 
 # Known text file extensions - always include these
-TEXT_EXTENSIONS=("sh" "bash" "zsh" "yaml" "yml" "json" "toml" "ini" "cfg" "conf" "txt" "md" "py" "js" "ts" "html" "css" "xml" "env" "service" "timer" "sql" "lua" "rb" "go" "rs" "java" "c" "h" "cpp" "hpp" "Makefile" "Dockerfile" "csv" "log" "properties" "rules")
+TEXT_EXTENSIONS=("sh" "bash" "zsh" "yaml" "yml" "json" "toml" "ini" "cfg" "conf" "txt" "md" "py" "js" "ts" "html" "css" "xml" "env" "service" "timer" "sql" "lua" "rb" "go" "mod" "sum" "rs" "java" "c" "h" "cpp" "hpp" "Makefile" "Dockerfile" "csv" "log" "properties" "rules")
 
 is_known_text() {
     local file="$1"
@@ -78,6 +79,20 @@ is_binary() {
     return 1
 }
 
+# Cat a file, stripping UTF-8 BOM if present (avoids inline BOMs in combined output)
+cat_strip_bom() {
+    local file="$1"
+    # Check if file starts with UTF-8 BOM (EF BB BF)
+    local header
+    header=$(head -c 3 "$file" | od -A n -t x1 | tr -d ' \n')
+    if [ "$header" = "efbbbf" ]; then
+        # Skip first 3 bytes (the BOM)
+        tail -c +4 "$file"
+    else
+        cat "$file"
+    fi
+}
+
 echo "=== Repo Collector ==="
 echo "Timestamp: $TIMESTAMP"
 echo "Working dir: $SCRIPT_DIR"
@@ -132,14 +147,16 @@ for repo_dir in */; do
     updated_repos+=("$repo_dir")
     echo "  Updating: ${repo_dir}/"
 
-    # Write header
+    # Write UTF-8 BOM + header
+    # printf writes raw bytes; echo writes the text header after it
+    printf '\xEF\xBB\xBF' > "$output_file"
     {
         echo "================================================================================"
         echo "Repository: ${repo_dir}"
         echo "Collected:  ${TIMESTAMP}"
         echo "================================================================================"
         echo ""
-    } > "$output_file"
+    } >> "$output_file"
 
     # Find all files, excluding skip dirs
     # First pass: collect READMEs
@@ -147,7 +164,7 @@ for repo_dir in */; do
         rel_path="${file#${repo_dir}/}"
         {
             echo "--- FILE: ${rel_path} ---"
-            cat "$file"
+            cat_strip_bom "$file"
             echo ""
             echo ""
         } >> "$output_file"
@@ -200,10 +217,10 @@ for repo_dir in */; do
             continue
         fi
 
-        # Include the file
+        # Include the file (strip BOM from source to avoid inline BOMs)
         {
             echo "--- FILE: ${rel_path} ---"
-            cat "$file"
+            cat_strip_bom "$file"
             echo ""
             echo ""
         } >> "$output_file"