feat(backend): PayerConfig with co_medicaid and generic factories

backend/tests/test_payer.py

@@ -0,0 +1,22 @@
+from cyclone.parsers.payer import PayerConfig
+
+
+def test_co_medicaid_defaults():
+    cfg = PayerConfig.co_medicaid()
+    assert cfg.name == "Colorado Medical Assistance Program"
+    assert cfg.sbr09_claim_filing == "MC"
+    assert cfg.allowed_claim_frequencies == {1, 7, 8}
+    assert cfg.require_ref_g1_for_adjustments is False  # lenient in v1
+    assert cfg.allowed_bht06 == {"CH"}
+    assert cfg.payer_id == "SKCO0"
+    assert cfg.payer_name == "COHCPF"
+    assert cfg.no_patient_loop is True
+    assert cfg.encounter_claim_in_same_batch is False
+
+
+def test_generic_837p_defaults_are_relaxed():
+    cfg = PayerConfig.generic_837p()
+    assert cfg.name == "Generic 837P"
+    assert cfg.allowed_claim_frequencies == {1, 2, 3, 4, 5, 6, 7, 8, 9}
+    assert cfg.no_patient_loop is False
+    assert cfg.payer_id == ""  # unset