Problem

The egress proxy Docker image build is failing for ARM64 architecture because the `squid` package is not available in Alpine Linux 3.22.1 repositories for the `aarch64` architecture.

Error Details

Failed Job: Build and Publish Egress Proxy Image

Error Message:
```
ERROR: unable to select packages:
squid (no such package):
required by: world[squid]
```

Build Context:

• The build succeeds for `linux/amd64` but fails for `linux/arm64`
• Alpine Linux 3.22.1 does not include the squid package in the ARM64 repositories
• The workflow builds for both platforms: `linux/amd64,linux/arm64`

Root Cause

The `squid` package has been removed or is not available in Alpine Linux 3.22.1 repositories for the ARM64 architecture, while it remains available for AMD64.

Proposed Solution

Use the Alpine edge repository to install squid, which contains the latest packages including squid for both architectures.

Dockerfile Change:
```dockerfile

Install squid from edge repository and create necessary directories

RUN echo "https://dl-cdn.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories
&& apk add --no-cache squid
&& mkdir -p /var/cache/squid /var/log/squid
&& chown -R squid:squid /var/cache/squid /var/log/squid /var/run/squid
&& chmod 750 /var/cache/squid /var/log/squid
```

Impact

• Severity: High - Blocks multi-architecture image builds
• Affected Components: Egress proxy container image
• Platforms Affected: ARM64/aarch64 only

Testing

The proposed fix has been tested locally and successfully builds for both `linux/amd64` and `linux/arm64` architectures.