Standardize SurClaw ports away from defaults

- Change the API default listen port from 3000 to 3100 and include the Docker frontend origin in default CORS.

- Point Vite's default API proxy, Docker API container port, and Nginx upstream to 3100.

- Keep Docker host ports on 4002 for web, 3002 for API, and 5433 for PostgreSQL.

- Update environment examples and documentation to remove stale localhost:3000 guidance.

Dockerfile.server

@@ -17,5 +17,5 @@ COPY --from=builder /app/server/dist ./server/dist
 COPY --from=builder /app/server/prisma ./server/prisma
 COPY --from=builder /app/prisma.config.ts ./prisma.config.ts
 COPY --from=builder /app/node_modules/.prisma ./node_modules/.prisma
-EXPOSE 3000
+EXPOSE 3100
 CMD ["node", "server/dist/main.js"]