Fix issues #8, #9, #10, #11: scheduling conflicts, med reminders, adaptive timing, nagging

- #11: Add validation to prevent simultaneous scheduling of routines and medications
  - Added _check_schedule_conflicts() in routines.py
  - Added _check_med_schedule_conflicts() in medications.py
  - Returns HTTP 409 with descriptive error on conflict

- #10: Fix medication reminders not being sent
  - Added call to check_adaptive_medication_reminders() in daemon poll loop

- #9: Fix can't enable adaptive timing
  - Added proper error handling and logging in update_adaptive_settings()
  - Returns meaningful error message on database failures

- #8: Fix nagging not working
  - Added debug logging for missing settings
  - Auto-create medication schedules if they don't exist
  - Improved error logging (warning -> error)

api/routes/routines.py

@@ -649,6 +649,40 @@ def register(app):
             )
         return flask.jsonify(result), 200
 
+    def _check_schedule_conflicts(user_uuid, new_days, new_time, exclude_routine_id=None):
+        """Check if the proposed schedule conflicts with existing routines or medications.
+        Returns (has_conflict, conflict_message) tuple.
+        """
+        if not new_days or not new_time:
+            return False, None
+
+        # Check conflicts with other routines
+        user_routines = postgres.select("routines", {"user_uuid": user_uuid})
+        for r in user_routines:
+            if r["id"] == exclude_routine_id:
+                continue
+            other_sched = postgres.select_one("routine_schedules", {"routine_id": r["id"]})
+            if other_sched and other_sched.get("time") == new_time:
+                other_days = json.loads(other_sched.get("days", "[]"))
+                if any(d in other_days for d in new_days):
+                    return True, f"Time conflicts with routine: {r.get('name', 'Unnamed routine')}"
+
+        # Check conflicts with medications
+        user_meds = postgres.select("medications", {"user_uuid": user_uuid, "active": True})
+        for med in user_meds:
+            med_times = med.get("times", [])
+            if isinstance(med_times, str):
+                med_times = json.loads(med_times)
+            if new_time in med_times:
+                # Check if medication runs on any of the same days
+                med_days = med.get("days_of_week", [])
+                if isinstance(med_days, str):
+                    med_days = json.loads(med_days)
+                if not med_days or any(d in med_days for d in new_days):
+                    return True, f"Time conflicts with medication: {med.get('name', 'Unnamed medication')}"
+
+        return False, None
+
     @app.route("/api/routines/<routine_id>/schedule", methods=["PUT"])
     def api_setRoutineSchedule(routine_id):
         """Set when this routine should run. Body: {days: ["mon","tue",...], time: "08:00", remind: true}"""
@@ -663,6 +697,16 @@ def register(app):
         data = flask.request.get_json()
         if not data:
             return flask.jsonify({"error": "missing body"}), 400
+
+        # Check for schedule conflicts
+        new_days = data.get("days", [])
+        new_time = data.get("time")
+        has_conflict, conflict_msg = _check_schedule_conflicts(
+            user_uuid, new_days, new_time, exclude_routine_id=routine_id
+        )
+        if has_conflict:
+            return flask.jsonify({"error": conflict_msg}), 409
+
         existing = postgres.select_one("routine_schedules", {"routine_id": routine_id})
         schedule_data = {
             "routine_id": routine_id,