Add RCS experiment (#461)

* Add RCS experiment

* typo

* fix docstrings

* Add Gemini Code Assist config file (#462)

This configures Gemini Code Assist to be a little bit less noisy and
verbose. Based on experiences with other repos, I find this makes Gemini
more useful.

* addressed comments

* Fix incompatible return value found by typecheck

And make it bit more apparent how is `RCSResults._fidelities_lin` set.

Fixes  mypy recirq/random_circuit_sampling | grep random_circuit

* Update recirq/random_circuit_sampling/rcs_experiment.py

Co-authored-by: Pavol Juhas <pavol.juhas@gmail.com>

* Update recirq/random_circuit_sampling/rcs_experiment.py

Co-authored-by: Pavol Juhas <pavol.juhas@gmail.com>

* Update recirq/random_circuit_sampling/rcs_experiment.py

Co-authored-by: Pavol Juhas <pavol.juhas@gmail.com>

* addressed Alexis's comments

---------

Co-authored-by: Shashwat Kumar <kshashwat@google.com>
Co-authored-by: Michael Hucka <mhucka@google.com>
Co-authored-by: Pavol Juhas <juhas@google.com>
Co-authored-by: Pavol Juhas <pavol.juhas@gmail.com>

Author: 4 people

recirq/random_circuit_sampling/__init__.py

@@ -0,0 +1,21 @@
+# Copyright 2026 Google
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from recirq.random_circuit_sampling.rcs_experiment import (
+    characterize_pairs,
+    make_rcs_circuit,
+    RCSExperiment,
+    RCSResults,
+)