rework dev server: hmr for all courses, per-course targets, root index

- make dev serves all courses on port 1312 with marp live reload
- make dev-b/dev-c for single course on 1313/1314
- dev-kill only kills specific ports instead of all marp processes
- add generate-root-index.sh for prod build overview page
- cleanup function uses exec + trap instead of pid files

scripts/dev-server.sh

@@ -1,12 +1,16 @@
 #!/usr/bin/env bash
-# Simplified development server for HdM slides
-# Starts single Marp server for all courses
+# Development server for HdM slides
+# Usage:
+#   ./dev-server.sh              - Marp live server for all courses (port 1312)
+#   ./dev-server.sh 223015b 1313 - Marp live server for single course
+#   ./dev-server.sh 223015c 1314 - Marp live server for single course
 
 set -e
 
 # Configuration
 SLIDES_DIR="slides"
-DEV_PORT=3000
+COURSE="${1:-}"
+DEV_PORT="${2:-1312}"
 
 # Colors
 GREEN='\033[0;32m'
@@ -14,40 +18,27 @@ BLUE='\033[0;34m'
 RED='\033[0;31m'
 NC='\033[0m' # No Color
 
-# Cleanup function
-cleanup() {
-    echo -e "\n${RED}Shutting down dev server...${NC}"
-    pkill -f "marp-cli.*--server" 2>/dev/null || true
-    exit 0
-}
-
-# Kill existing processes on our port
-kill_existing() {
-    echo -e "${BLUE}Cleaning up existing processes...${NC}"
-    pkill -9 -f "marp-cli" 2>/dev/null || true
-    fuser -k $DEV_PORT/tcp 2>/dev/null || true
-    sleep 1
+# Kill existing process on our port only
+kill_port() {
+    fuser -k "$DEV_PORT/tcp" 2>/dev/null || true
+    sleep 0.5
 }
 
 # Main
-trap cleanup SIGINT SIGTERM
+trap 'echo -e "\n${RED}Shutting down...${NC}"; kill 0; exit 0' SIGINT SIGTERM
 
-kill_existing
+kill_port
 
-echo -e "${GREEN}Starting development server...${NC}"
-echo ""
-echo -e "  Server:   ${BLUE}http://localhost:$DEV_PORT${NC}"
-echo -e "  Slides:   ${BLUE}$SLIDES_DIR/${NC}"
-echo ""
-echo -e "Available courses:"
-echo -e "  223015b: ${BLUE}http://localhost:$DEV_PORT/223015b/${NC}"
-echo -e "  223015c: ${BLUE}http://localhost:$DEV_PORT/223015c/${NC}"
-echo ""
-echo -e "Press ${RED}Ctrl+C${NC} to stop the server"
+if [ -n "$COURSE" ]; then
+    SERVE_DIR="$SLIDES_DIR/$COURSE"
+    echo -e "${GREEN}Marp dev server${NC} · ${BLUE}$COURSE${NC}"
+else
+    SERVE_DIR="$SLIDES_DIR"
+    echo -e "${GREEN}Marp dev server${NC} · ${BLUE}all courses${NC}"
+fi
+
+echo -e "  ${BLUE}http://localhost:$DEV_PORT${NC}"
+echo -e "  ${BLUE}$SERVE_DIR/${NC}"
 echo ""
 
-# Start single Marp server for all slides
-PORT=$DEV_PORT npx @marp-team/marp-cli --server "$SLIDES_DIR/"
-
-# Wait for process to exit
-wait
+PORT=$DEV_PORT exec npx @marp-team/marp-cli --server "$SERVE_DIR/"