Development environment setup for target autodiscovery

[denyost]

• Introduced the initial folder and file structure for the target autodiscovery feature.
• Added temporary NetBox management support to the Makefile to facilitate target autodiscovery development (development-only; will be removed after implementation).
• Included an Arista router in the Containerlab setup, along with the necessary gNMIc CRs for monitoring, to support target autodiscovery development (development-only; will be removed after implementation).

[cloudflare-workers-and-pages]

Deploying gnmic-operator with    Cloudflare Pages

Latest commit:	fc7f38e
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View logs

[denyost]

@karimra The pull request fails because setup-envtest is pinned to @latest, which now requires Go ≥ 1.26.0, while the CI uses Go 1.25.8.
There is already a pull request to upgrade the Go version: #31.

[denyost]

This PR now only prepares the development environment for target autodiscovery.

All TargetSource‑related changes and feature scaffolding were intentionally removed and have been moved to feature/target-loading-architecture.

The remaining changes are limited to development setup (Makefile helpers, Containerlab topology, and gNMIc CRs) and are development‑only.

[denyost]

The CI failure is unrelated to our changes. The integration test times out while waiting for the cluster to become ready, which suggests that the pod startup takes longer than the configured timeout:

kubectl wait --for=condition=Ready cluster --all --timeout=180s
error: timed out waiting for the condition on clusters/c1
make: *** [Makefile:303: run-integration-tests] Error 1
Error: Process completed with exit code 2.

[mcdillson]

@karimra I resolved the threads, should be ready to merge