Refactor: responsive upload page, fix warnings, CI/CD setup

- Fix MUI v4/React 18 StrictMode warnings (justify→justifyContent, Button migration)
- Responsive UploadDiary: footer visible without scroll, mobile layout centered, overview text hidden on mobile
- Fix Redux selector memoization with createSelector
- RSS sync: auto-refresh PosterSelector after sync, Snackbar feedback with film count
- Add .gitea/workflows/deploy.yml for tag-based CI/CD
- Fix nginx config (default.conf), increase Node heap for Docker build
- Update README

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -5,7 +5,7 @@ WORKDIR /app
 
 COPY package*.json ./
 
-ENV NODE_OPTIONS="--max-old-space-size=512"
+ENV NODE_OPTIONS="--max-old-space-size=2048"
 RUN npm ci --silent --legacy-peer-deps
 
 COPY . .
@@ -22,7 +22,7 @@ FROM nginx:stable-alpine AS runner
 # Copy build output
 COPY --from=builder /app/build /usr/share/nginx/html
 
-COPY nginx-spa.conf /etc/nginx/conf.d/nginx-spa.conf
+COPY nginx-spa.conf /etc/nginx/conf.d/default.conf
 
 # Expose port 80 (Caddy fera reverse proxy)
 EXPOSE 80