fix: migrate dev Dockerfile from Docker to UBI

Replace golang:1.24-alpine with
registry.access.redhat.com/ubi9/go-toolset:1.24. Remove apk install of
git and build-base as go-toolset already includes them.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Martin Prpič <mprpic@redhat.com>

Author: mprpic

components/backend/Dockerfile.dev

@@ -1,10 +1,11 @@
 # Development Dockerfile for Go backend (simplified, no Air)
-FROM golang:1.24-alpine
+FROM registry.access.redhat.com/ubi9/go-toolset:1.24
 
-WORKDIR /app
+USER 0
 
-# Install git and build dependencies
-RUN apk add --no-cache git build-base
+WORKDIR /app
+RUN chown -R 1001:0 /app
+USER 1001
 
 # Set environment variables
 ENV AGENTS_DIR=/app/agents