feat: ESCALATE verdict, issue tracker, onboarding commands

Add 3-verdict system (PASS/FAIL/ESCALATE) with priority handling across
simple and phased pipelines. Senior reviewers can now escalate issues
requiring human intervention, immediately breaking the review loop.

- ESCALATE verdict extraction with highest priority over PASS/FAIL
- Issue Tracker tables (ISS-NNN) carried across iterations
- Auto-escalate heuristic using (file, keyword) composite fingerprints
- Report restructuring: executive view first (verdict → tracker → metrics)
- Onboarding: `doctor`, `demo`, `init --guided` commands
- Exit codes: PASS=0, FAIL=1, ESCALATE=2
- 87 tests passing (54 config + 25 onboarding + 8 integration)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cross_eval.egg-info/SOURCES.txt

@@ -4,6 +4,8 @@ cross_eval/__init__.py
 cross_eval/agent.py
 cross_eval/cli.py
 cross_eval/config.py
+cross_eval/demo.py
+cross_eval/doctor.py
 cross_eval/models.py
 cross_eval/pipeline.py
 cross_eval/prompts.py
@@ -14,4 +16,6 @@ cross_eval.egg-info/dependency_links.txt
 cross_eval.egg-info/entry_points.txt
 cross_eval.egg-info/requires.txt
 cross_eval.egg-info/top_level.txt
-tests/test_config.py
+tests/test_config.py
+tests/test_onboarding.py
+tests/test_pipeline_integration.py