fix: unwrap single-key kaizen resolver payloads in resolve_context

When discover_kaizen_projects returns {"projects": [...]} bound to
context.projects, for_each can iterate the list directly. Multi-key
summaries (e.g. repo SBOM bulk) remain unchanged.

src/activity_core/activities.py

@@ -13,6 +13,7 @@ from __future__ import annotations
 
 import uuid
 from datetime import datetime, timezone
+from typing import Any
 
 from sqlalchemy import select
 from sqlalchemy.dialects.postgresql import insert as pg_insert
@@ -52,6 +53,18 @@ def _get_session_factory() -> async_sessionmaker[AsyncSession]:
     return _session_factory
 
 
+def _bind_resolver_result(bind_key: str, result: Any) -> Any:
+    """Unwrap single-key resolver payloads when the key matches bind_key.
+
+    Resolvers such as ``discover_kaizen_projects`` return ``{"projects": [...]}``
+    while definitions bind to ``context.projects`` and iterate ``for_each:
+    context.projects``.  Multi-key summaries (e.g. repo SBOM bulk) stay intact.
+    """
+    if isinstance(result, dict) and len(result) == 1 and bind_key in result:
+        return result[bind_key]
+    return result
+
+
 # ── Activities ─────────────────────────────────────────────────────────────────
 
 @activity.defn
@@ -139,7 +152,8 @@ async def resolve_context(
             continue
 
         try:
-            snapshot[bind_key] = resolver_cls().resolve(query, None, params)
+            resolved = resolver_cls().resolve(query, None, params)
+            snapshot[bind_key] = _bind_resolver_result(bind_key, resolved)
         except Exception as exc:
             if required:
                 raise ApplicationError(

tests/test_resolve_context_binding.py

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+import pytest
+
+from activity_core.activities import _bind_resolver_result, resolve_context
+
+
+def test_bind_resolver_result_unwraps_single_key_wrapper() -> None:
+    projects = [{"repo": "kaizen-agentic", "has_metrics": True}]
+    assert _bind_resolver_result("projects", {"projects": projects}) == projects
+
+
+def test_bind_resolver_result_keeps_multi_key_summary() -> None:
+    summary = {
+        "repos": [{"repo_slug": "a"}],
+        "stale_count": 1,
+        "total_count": 2,
+    }
+    assert _bind_resolver_result("repos", summary) == summary
+
+
+@pytest.mark.asyncio
+async def test_resolve_context_unwraps_kaizen_projects(monkeypatch) -> None:
+    class _FakeResolver:
+        def resolve(self, query: str, event: object, params: dict) -> dict:
+            assert query == "discover_kaizen_projects"
+            return {"projects": [{"repo": "pilot", "has_metrics": True}]}
+
+    import activity_core.context_resolvers  # noqa: F401
+    from activity_core.context_resolvers.base import CONTEXT_RESOLVER_REGISTRY
+
+    monkeypatch.setitem(CONTEXT_RESOLVER_REGISTRY, "kaizen", lambda: _FakeResolver())
+
+    snapshot = await resolve_context(
+        [
+            {
+                "type": "kaizen",
+                "query": "discover_kaizen_projects",
+                "params": {},
+                "bind_to": "context.projects",
+            }
+        ]
+    )
+
+    assert snapshot == {"projects": [{"repo": "pilot", "has_metrics": True}]}