feat: add preflight checks and version extraction

Made-with: Cursor

build.sh

@@ -34,6 +34,32 @@ success() { echo -e "${GREEN}✓${NC} $1"; }
 warn()    { echo -e "${YELLOW}⚠${NC} $1"; }
 error()   { echo -e "${RED}✗${NC} $1"; }
 
+get_version_name() {
+    grep 'versionName' "$GRADLE_BUILD_FILE" | head -1 | sed 's/.*"\(.*\)".*/\1/'
+}
+
+preflight_check() {
+    local ok=true
+
+    if ! command -v java &>/dev/null && [[ -z "${JAVA_HOME:-}" ]]; then
+        error "Java not found. Install JDK 17+ or set JAVA_HOME."
+        ok=false
+    fi
+
+    if [[ ! -x "./gradlew" ]]; then
+        error "Gradle wrapper not found or not executable."
+        ok=false
+    fi
+
+    if [[ "$ok" != true ]]; then
+        exit 1
+    fi
+}
+
+ensure_dist_dir() {
+    mkdir -p "$DIST_DIR"
+}
+
 main_menu() {
     echo -e "${BOLD}What would you like to do?${NC}"
     echo ""
@@ -63,6 +89,7 @@ manage_keystore()  { warn "Not yet implemented"; }
 clean_build()      { warn "Not yet implemented"; }
 
 # --- Main ---
+preflight_check
 banner
 while true; do
     main_menu