Added sanity check baseline made by claude.

Also changed the location to a panel in VIEW_3D instead of menu.

core/__init__.py

@@ -0,0 +1,37 @@
+"""Public API of the sanity check framework.
+
+Checks only need::
+
+    from ...core import Check, Issue, Severity, SkipCheck, contexts
+"""
+
+from . import contexts
+from .check import (
+    Check,
+    CheckContext,
+    Issue,
+    Severity,
+    SkipCheck,
+    all_checks,
+    checks_for_context,
+    get_check,
+    is_local,
+)
+from .runner import Report, Status, fix_check, run_checks
+
+__all__ = [
+    "Check",
+    "CheckContext",
+    "Issue",
+    "Report",
+    "Severity",
+    "SkipCheck",
+    "Status",
+    "all_checks",
+    "checks_for_context",
+    "contexts",
+    "fix_check",
+    "get_check",
+    "is_local",
+    "run_checks",
+]