feat: add per-space timezone settings and improve booking management

- Add timezone configuration per space with fallback to system default
- Implement timezone-aware datetime display and editing across frontend
- Add migration for per_space_settings table
- Update booking service to handle timezone conversions properly
- Improve .gitignore to exclude build artifacts
- Add comprehensive testing documentation

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

start.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+set -e
+
+PROJECT_DIR="$(cd "$(dirname "$0")" && pwd)"
+BACKEND_DIR="$PROJECT_DIR/backend"
+FRONTEND_DIR="$PROJECT_DIR/frontend"
+
+# Colors
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m'
+
+cleanup() {
+    echo -e "\n${YELLOW}Stopping services...${NC}"
+    kill $BACKEND_PID $FRONTEND_PID 2>/dev/null
+    wait $BACKEND_PID $FRONTEND_PID 2>/dev/null
+    echo -e "${GREEN}Done.${NC}"
+}
+trap cleanup EXIT
+
+# Backend setup
+echo -e "${GREEN}[Backend] Setting up...${NC}"
+if [ ! -d "$BACKEND_DIR/venv" ]; then
+    python3 -m venv "$BACKEND_DIR/venv"
+    source "$BACKEND_DIR/venv/bin/activate"
+    pip install -q -r "$BACKEND_DIR/requirements.txt"
+else
+    source "$BACKEND_DIR/venv/bin/activate"
+fi
+
+# Seed DB if empty
+if [ ! -f "$BACKEND_DIR/space_booking.db" ]; then
+    echo -e "${GREEN}[Backend] Seeding database...${NC}"
+    cd "$BACKEND_DIR" && python seed_db.py
+fi
+
+echo -e "${GREEN}[Backend] Starting on :8000${NC}"
+cd "$BACKEND_DIR" && uvicorn app.main:app --reload --host 0.0.0.0 --port 8000 &
+BACKEND_PID=$!
+
+# Frontend setup
+echo -e "${GREEN}[Frontend] Setting up...${NC}"
+if [ ! -d "$FRONTEND_DIR/node_modules" ]; then
+    cd "$FRONTEND_DIR" && npm install --silent
+fi
+
+echo -e "${GREEN}[Frontend] Starting on :5173${NC}"
+cd "$FRONTEND_DIR" && npm run dev -- --host 0.0.0.0 &
+FRONTEND_PID=$!
+
+echo -e "\n${GREEN}=== Space Booking Running ===${NC}"
+echo -e "  Backend:  http://localhost:8000"
+echo -e "  Frontend: http://localhost:5173"
+echo -e "  API Docs: http://localhost:8000/docs"
+echo -e "${YELLOW}  Press Ctrl+C to stop${NC}\n"
+
+wait