chore(docker): bump python from 3.9-slim to 3.14-slim in /backend

backend/Dockerfile

@@ -1,6 +1,6 @@
 # Simple Python backend Dockerfile for OpsSight Backend
 
-FROM python:3.11-slim
+FROM python:3.14-slim
 
 WORKDIR /app
 

backend/Dockerfile.dev

@@ -1,7 +1,7 @@
 # OpsSight Backend - Development Dockerfile
 # Multi-stage build for development with hot reload and debugging
 
-FROM python:3.9-slim as base
+FROM python:3.14-slim as base
 
 # Set environment variables
 ENV PYTHONUNBUFFERED=1 \

backend/Dockerfile.prod

@@ -1,5 +1,5 @@
 # Multi-stage production Dockerfile for OpsSight Backend
-FROM python:3.11-alpine AS builder
+FROM python:3.14-alpine AS builder
 
 # Install build dependencies
 RUN apk add --no-cache \
@@ -19,7 +19,7 @@ COPY requirements-minimal.txt .
 RUN pip install --no-cache-dir --user -r requirements-minimal.txt
 
 # Production stage
-FROM python:3.11-alpine AS production
+FROM python:3.14-alpine AS production
 
 # Install runtime dependencies
 RUN apk add --no-cache \