Validation: unify CLI reports and add a strict publish profile

[zkwentz]

What & Why

Publishing needs a stricter answer than ordinary local iteration: every blocking criterion must actually run and pass. This PR unifies CLI execution on the shared planner and adds the strict publish profile.

Risk & Review Guidance

• Risk level: MEDIUM — changes validation exit semantics for the new publish path
• Task class: feature
• Review focus: src/openenv/cli/commands/validate.py:30 for unified dispatch; src/openenv/validation/models.py:626 for publish aggregation; tests/test_validation/test_executor.py for blocking-skip behavior
• Blast radius: Incorrect aggregation could publish an incomplete environment or block a valid one.

Decisions & Alternatives

• Blocking skip fails only the publish gate — static/runtime/full remain useful for partial local iteration.
• Remove the legacy semantic split — rejected maintaining a second validator with different criteria.
• Remote defaults to publish — isolation is primarily the pre-publish author path.

Verification

• PASS: PYTHONPATH=src:envs .venv/bin/python -m pytest tests/ -q -m 'not integration' — 1,559 passed, 114 skipped, 31 external integration tests deselected on the complete stack.
• PASS: Fork whole-stack CI — 7/7 checks passed, including Python 3.11/3.12, lint, docs, lock validation, and package smoke tests.
• NOT verified: No live remote execution is part of this layer.

Scope & Non-Goals

• This PR does not yet create the remote Sandbox or wire the gate into openenv push.

Breaking Changes / Migration Notes

The new publish profile intentionally exits non-zero for blocking skips; existing static/runtime/full behavior remains less strict.

Stack

PR 10 of 17; depends on #950.

Full 17-PR stack

1. #942 RFC 008: Spec-neutral local and remote validation architecture
2. #943 Validation foundation: spec-neutral contracts and adapters
3. #944 Validation policy: spec-aware check registry and planner
4. #945 Validation executor: hardened shared reports and eligibility
5. #946 Local validation API: execution-model-aware profiles
6. #947 CLI: validation profiles and shared reports
7. #948 HF runtime: dedicated sandbox execution mode
8. #949 HF certification: enforce trusted dedicated isolation
9. #950 [RFC 008] Define remote author validation and publish gating
10. #951 Validation: unify CLI reports and add a strict publish profile ← current
11. #952 Validation: add structured author diagnostics and remediation
12. #953 Validation: run author validation in dedicated HF Sandboxes
13. #954 Validation: isolate submitted code in author Sandboxes
14. #955 Validation: bind author reports to policy and source
15. #956 CLI: scaffold publish requirements
16. #957 CLI: gate pushes on staged remote validation
17. #958 Docs: explain local, remote, and publish validation

All upstream PRs remain draft while RFC 008 is under review.