feat: remove nginx, add projects/milestones/notifications pages

- Dockerfile: replace nginx with serve for static files
- Fix auth endpoint: /auth/login → /auth/token
- Add ProjectsPage, ProjectDetailPage
- Add MilestonesPage, MilestoneDetailPage with progress bar
- Add NotificationsPage with unread count
- Sidebar: add milestones/notifications nav, live unread badge
- API: configurable VITE_API_BASE for host nginx proxy
- Types: add Milestone, MilestoneProgress, Notification, ProjectMember

Dockerfile

@@ -1,12 +1,17 @@
+# Build stage
 FROM node:20-alpine AS build
 WORKDIR /app
-COPY package.json ./
+COPY package.json package-lock.json* ./
 RUN npm install
 COPY . .
+ARG VITE_API_BASE=/api
+ENV VITE_API_BASE=$VITE_API_BASE
 RUN npm run build
 
-FROM nginx:alpine
-COPY --from=build /app/dist /usr/share/nginx/html
-COPY nginx.conf /etc/nginx/conf.d/default.conf
+# Production stage — lightweight static server, no nginx
+FROM node:20-alpine
+RUN npm install -g serve@14
+WORKDIR /app
+COPY --from=build /app/dist ./dist
 EXPOSE 3000
-CMD ["nginx", "-g", "daemon off;"]
+CMD ["serve", "-s", "dist", "-l", "3000"]