refactor: extract shared get_public_ip into helpers.sh

[mehmetkr-31]

Summary

Eliminates 23-line duplication of get_public_ip() across op-node-entrypoint and base-consensus-entrypoint by moving it into a shared helpers.sh script.

Problem

The get_public_ip() bash function was copy-pasted verbatim in two entrypoints. This violates DRY:

• Any bug fix or provider list change must be edited twice.
• The two copies can silently diverge over time.

Solution

1. Create helpers.sh containing a single, documented get_public_ip implementation.
2. Replace inline definitions with source ./helpers.sh in both entrypoints.
3. Add COPY helpers.sh . to geth, reth, and nethermind Dockerfiles so the helper is present in all final images.

Files Changed

File	Change
helpers.sh	New — shared helper library
op-node-entrypoint	Remove inline get_public_ip, add source ./helpers.sh
base-consensus-entrypoint	Same as above
geth/Dockerfile	COPY helpers.sh .
reth/Dockerfile	COPY helpers.sh .
nethermind/Dockerfile	COPY helpers.sh .

Verification

• get_public_ip is still callable from both entrypoints.
• Docker build context includes helpers.sh at repo root, so all COPY instructions resolve.
• No functional change; behavior is identical.

Impact

• Reduces maintenance burden for future IP-detection changes.
• Establishes a pattern for shared helper functions across entrypoints.

Checklist

• Refactor only — no functional changes.
• All three client Dockerfiles updated.
• Verified that source ./helpers.sh resolves inside the container (/app).

[cb-heimdall]

🟡 Heimdall Review Status

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