feat: config loader with toml + env override

tests/test_config.py

@@ -0,0 +1,26 @@
+import os
+from pathlib import Path
+import pytest
+from chat.config import load_settings
+
+def test_load_settings_reads_toml(tmp_path, monkeypatch):
+    cfg = tmp_path / "config.toml"
+    cfg.write_text("""
+        featherless_api_key = "sk-test"
+        narrative_model = "dphn/Dolphin-Mistral-24B-Venice-Edition"
+        classifier_model = "NousResearch/Hermes-3-Llama-3.1-8B"
+        ooc_marker = "(("
+        retrieval_k = 4
+    """)
+    monkeypatch.setenv("CHAT_CONFIG_PATH", str(cfg))
+    s = load_settings()
+    assert s.featherless_api_key == "sk-test"
+    assert s.narrative_model.startswith("dphn/")
+    assert s.retrieval_k == 4
+
+def test_chat_db_path_env_overrides_default(tmp_path, monkeypatch):
+    monkeypatch.setenv("CHAT_DB_PATH", str(tmp_path / "alt.db"))
+    monkeypatch.setenv("CHAT_CONFIG_PATH", str(tmp_path / "config.toml"))
+    (tmp_path / "config.toml").write_text('featherless_api_key = "x"\n')
+    s = load_settings()
+    assert s.db_path == tmp_path / "alt.db"