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

src/loop/runner.py

@@ -0,0 +1,40 @@
+"""Loop runner — orchestrates the three phases in sequence.
+
+Runs Gather → Reason → Act as a single cycle, passing output from each
+phase as input to the next. The Act output feeds back as input to the
+next Gather call.
+"""
+
+from __future__ import annotations
+
+import logging
+
+from loop.phase1_gather import gather
+from loop.phase2_reason import reason
+from loop.phase3_act import act
+from loop.schema import ContextPayload
+
+logger = logging.getLogger(__name__)
+
+
+def run_cycle(payload: ContextPayload) -> ContextPayload:
+    """Execute one full Gather → Reason → Act cycle.
+
+    Returns the Act phase output, which can be fed back as input
+    to the next cycle.
+    """
+    logger.info("=== Loop cycle start: source=%s ===", payload.source)
+
+    gathered = gather(payload)
+    reasoned = reason(gathered)
+    acted = act(reasoned)
+
+    logger.info(
+        "=== Loop cycle complete: phases=%s ===",
+        [
+            gathered.metadata.get("phase"),
+            reasoned.metadata.get("phase"),
+            acted.metadata.get("phase"),
+        ],
+    )
+    return acted