fix(docs): read observation history before curating facts in memories.py (#2120)

memories.py listed memories, then ran edit -> invalidate -> restore on a fact.
Any update_memory call re-consolidates the bank and recreates derived
observations with new ids, so the observation id from the earlier listing was
stale by the time the example called get_observation_history — which the engine
correctly 404s on (NotFoundException), failing test-doc-examples (python) on
every PR.

Move the observation-history read to immediately after list_memories, before
the curate operations, so it uses a live id. No re-consolidation timing
dependency. The existing `if observation is not None` guard still covers the
no-observation case.

Author: DK09876

hindsight-docs/examples/api/memories.py

@@ -38,6 +38,20 @@ async def main():
     print(f"{len(invalidated.items)} invalidated fact(s)")
     # [/docs:list-memories]
 
+    # An observation (derived) exposes how it evolved as sources arrived. Read
+    # it here, before the edit/invalidate/restore below: any update_memory call
+    # re-consolidates and recreates observations with new ids, so an id captured
+    # before those steps is stale afterward (get_observation_history would 404).
+    observation = next((u for u in memories.items if u["fact_type"] == "observation"), None)
+    if observation is not None:
+        # [docs:observation-history]
+        # Get the refresh history of a derived observation.
+        history = await client.memory.get_observation_history(
+            bank_id=BANK_ID, memory_id=observation["id"]
+        )
+        print(f"Observation history entries: {len(history)}")
+        # [/docs:observation-history]
+
     # Grab a raw fact (world/experience) to curate in the examples below.
     fact = next((u for u in memories.items if u["fact_type"] in ("world", "experience")), None)
     if fact is None:
@@ -103,17 +117,6 @@ async def main():
     )
     # [/docs:restore-memory]
 
-    # An observation (derived) exposes how it evolved as sources arrived.
-    observation = next((u for u in memories.items if u["fact_type"] == "observation"), None)
-    if observation is not None:
-        # [docs:observation-history]
-        # Get the refresh history of a derived observation.
-        history = await client.memory.get_observation_history(
-            bank_id=BANK_ID, memory_id=observation["id"]
-        )
-        print(f"Observation history entries: {len(history)}")
-        # [/docs:observation-history]
-
     # =========================================================================
     # Cleanup (not shown in docs)
     # =========================================================================