[Harbor] Add a real Harbor 0.22.x Docker end-to-end smoke gate

[reacher-z]

Problem

The Harbor compatibility test is skipped when Harbor is not installed, and CI does not execute a real harbor run. The Harbor runtime Dockerfile is also outside the current harness image build scan. This leaves adapter, image, runtime readiness, verifier, and cleanup regressions undetected.

Required scope

• Pin Harbor 0.22.x and Python 3.12 in a Linux Docker job.
• Convert one real V2 task and validate it with Harbor's loader.
• Run a single Harbor task smoke covering setup, runtime readiness, verifier, artifact collection, and cleanup.
• Include src/clawbench/runtime/harbor/Dockerfile in the image build matrix.
• Upload task/runtime/verifier logs on failure and record Harbor/schema/image versions.

Acceptance criteria

• Adapter/runtime changes require the Harbor smoke job.
• The job exercises successful interception, no interception, judge-inconclusive, and cleanup failure paths.
• Harbor artifacts are available for debugging without exposing credentials.

This is HAR-001 in docs/codebase-evaluation-2026-09.md and is related to #331. @Perry2004 please review the support matrix and CI cost.

[Perry2004]

The Harbor adaptor is under active development and we're still finding the best way to fit ClawBench with Harbor's pattern. CIs will be added after we've settled.