docs(workspace): document Harbor execution boundary

[christso]

Summary

AgentV docs now make the workspace ownership boundary explicit: native workspaces stay responsible for generic repo acquisition, CI gates, target comparisons, hooks, and AgentV run bundles, while Harbor-owned standard benchmark suites stay behind a launch/import/gate boundary.

This also locks in the checkout naming contract from the workspace split: workspace.repos[].commit is canonical, and base_commit is only a SWE-Bench-friendly alias for the same value. The new ADR defines the minimal future Harbor runner surface around execution.runner: harbor, a nested execution.harbor block, mutually exclusive dataset/config selectors, and explicit non-goals for Harbor task.toml, verifier packaging, and pass-through adapter fields.

Refs #1392.

Validation

• bun run validate:examples passed: 60 valid eval YAML files.
• bun run verify passed: build, typecheck, lint, core tests, eval tests, phoenix adapter tests, CLI tests, and dashboard tests.
• bun --filter @agentv/web build passed for the MDX docs pages.
• Pre-push hook passed: typecheck plus Biome.
• Code review: skipped. This is a docs/ADR-only change, no Tier 1 review tool is available in this harness, and Tier 2 escalation criteria were not met.

Post-Deploy Monitoring & Validation

No additional operational monitoring required. This PR changes documentation and an ADR only, with no runtime code path, schema parser, CLI command, API response, or deployment behavior changed.

Healthy signal after merge: the docs deployment builds successfully and the Workspace Architecture and Benchmark Provenance pages render.

Failure signal: docs build or link/frontmatter validation fails in CI. Mitigation is to revert or patch the affected MDX/ADR text.

Validation window and owner: PR author during CI and docs deploy for this PR.

---

[christso]

No findings.

I reviewed the docs/ADR changes against current workspace repo parsing and validation. The PR preserves native AgentV workspace semantics, describes commit as the canonical checkout pin with base_commit as a matching SWE-Bench-friendly alias, and keeps Harbor behind a delegated launch/import/gate runner boundary instead of copying Harbor task schema into AgentV core.

Verification run locally:

• bun run validate:examples passed: 60 valid eval YAML files.
• bun --filter @agentv/web build passed after bun install --frozen-lockfile in this fresh worktree.
• git diff --check origin/main...HEAD passed.

I also checked current PR status with gh pr checks: Build, Check Links, Cloudflare Pages, Lint, Test, Typecheck, Validate Evals, and Validate Marketplace are all passing.

Residual risk: the Harbor YAML surface is an ADR/docs design for future implementation, not a runtime path in this PR. I did not validate a live Harbor integration because this change intentionally adds no Harbor runner code, and the public docs example is explicitly labeled as proposed rather than current AgentV task schema.