[loop-cycle-65] feat: scaffold three-phase loop skeleton (#324) (#330)

src/loop/phase3_act.py

@@ -0,0 +1,36 @@
+"""Phase 3 — Act: accept reasoning output, execute and produce feedback.
+
+This is the command phase. It receives the reasoning result from Phase 2
+and takes action. In the stub form, it passes the payload through with a
+phase marker and produces feedback for the next cycle.
+"""
+
+from __future__ import annotations
+
+import logging
+
+from loop.schema import ContextPayload
+
+logger = logging.getLogger(__name__)
+
+
+def act(payload: ContextPayload) -> ContextPayload:
+    """Accept reasoning result and return action output + feedback.
+
+    Stub: tags the payload with phase=act and logs transit.
+    Timmy will flesh this out with tool execution, delegation,
+    response generation, and feedback construction.
+    """
+    logger.info(
+        "Phase 3 (Act) received: source=%s reasoned=%s",
+        payload.source,
+        payload.metadata.get("reasoned", False),
+    )
+
+    result = payload.with_metadata(phase="act", acted=True)
+
+    logger.info(
+        "Phase 3 (Act) produced: metadata_keys=%s",
+        sorted(result.metadata.keys()),
+    )
+    return result