feat: add Unix socket support for inter-container communication

[AlinsRan]

Type of change:

• Bugfix
• New feature provided
• Improve performance
• Backport patches
• Documentation
• Refactor
• Chore
• CI/CD or Tests

What this PR does / why we need it:

Currently, inter-container communication within the same Pod relies on HTTP over TCP (loopback or pod IP).
This approach introduces unnecessary networking overhead and requires opening or allocating TCP ports, even though the traffic never leaves the Pod.

By using Unix domain sockets (UDS), we can:

• Reduce overhead for local inter-container communication

• Eliminate the need to expose or bind TCP ports within the Pod

• Improve security by leveraging file system permissions to control access

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first