fix(backend): include steps in list_routines response

Batch-load all routine steps in a single query and attach them to each
routine dict, mirroring the detail endpoint pattern. Fixes "0 steps"
shown on the routines list page.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/innercontext/api/routines.py

@@ -290,7 +290,7 @@ ZASADY:
 # ---------------------------------------------------------------------------
 
 
-@router.get("", response_model=list[Routine])
+@router.get("")
 def list_routines(
     from_date: Optional[date] = None,
     to_date: Optional[date] = None,
@@ -304,7 +304,25 @@ def list_routines(
         stmt = stmt.where(Routine.routine_date <= to_date)
     if part_of_day is not None:
         stmt = stmt.where(Routine.part_of_day == part_of_day)
-    return session.exec(stmt).all()
+    routines = session.exec(stmt).all()
+
+    routine_ids = [r.id for r in routines]
+    steps_by_routine: dict = {}
+    if routine_ids:
+        all_steps = session.exec(
+            select(RoutineStep).where(RoutineStep.routine_id.in_(routine_ids))
+        ).all()
+        for step in all_steps:
+            steps_by_routine.setdefault(step.routine_id, []).append(step)
+
+    result = []
+    for r in routines:
+        data = r.model_dump(mode="json")
+        data["steps"] = [
+            s.model_dump(mode="json") for s in steps_by_routine.get(r.id, [])
+        ]
+        result.append(data)
+    return result
 
 
 @router.post("", response_model=Routine, status_code=201)