refactor: centralize API keys, fix sqlite_db.py path, update docstrings

- config.py += FREE_LLM_API_KEY, LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY
- sqlite_db.py: use SQLITE_DB_PATH from constants
- n8n_desc.py: import FREE_LLM_API_KEY from config
- faq_route.py: import FREE_LLM_API_KEY from config
- live_monitor_route.py: import Langfuse keys from config
- prompt_optimizer_route.py: update docstrings (remove hardcoded IPs)
- NEW: tests/conftest.py with centralized BASE_URL

backend/api/common/faq_route.py

@@ -15,10 +15,10 @@ logger = logging.getLogger(__name__)
 router = APIRouter()
 
 # ── AI Config ──
-from config import LITELLM_BASE_URL
+from config import FREE_LLM_API_KEY, LITELLM_BASE_URL
 
 AI_BASE_URL = f"{LITELLM_BASE_URL}/v1/chat/completions"
-AI_API_KEY = "freellmapi-a858c30561987b8aa2a58343c7fe48a6a52e65cadb9df6d5"
+AI_API_KEY = FREE_LLM_API_KEY
 
 # ── DB Setup ──
 def _ensure_faqs_table():

backend/api/live_monitor/live_monitor_route.py

@@ -20,13 +20,10 @@ logger = logging.getLogger(__name__)
 router = APIRouter()
 
 # ─── Self-hosted Langfuse config ─────────────────────────────────
-from config import LANGFUSE_SELF_HOSTED_URL
+from config import LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, LANGFUSE_SELF_HOSTED_URL
 
 LANGFUSE_BASE = LANGFUSE_SELF_HOSTED_URL
-LANGFUSE_AUTH = (
-    "pk-lf-2bb249b1-77e3-4309-8954-312b8fb2fff9",
-    "sk-lf-bd0c7202-a7f4-4399-a36e-65ebe2e35104",
-)
+LANGFUSE_AUTH = (LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY)
 
 
 def _utc_now() -> datetime:

backend/api/product_desc/n8n_desc.py

@@ -27,10 +27,9 @@ logger = logging.getLogger(__name__)
 
 router = APIRouter(prefix="/api/product-desc", tags=["n8n Ultra Description"])
 
-from config import LITELLM_BASE_URL
+from config import FREE_LLM_API_KEY, LITELLM_BASE_URL
 
 # ── FreeLLMAPI config ──
-FREE_LLM_API_KEY = "freellmapi-a858c30561987b8aa2a58343c7fe48a6a52e65cadb9df6d5"
 
 VISION_MODEL = "meta-llama/llama-4-scout-17b-16e-instruct"
 WRITER_MODEL = "openai/gpt-oss-20b"

backend/api/prompt_optimizer/prompt_optimizer_route.py

@@ -3,7 +3,7 @@ Prompt Optimizer Route
 API endpoints cho Prompt Optimizer: test chatbot, judge responses, optimize prompts.
 
 Flow:
-1. run-test: Gọi chatbot API remote (172.16.2.207:5000) → lấy câu trả lời
+1. run-test: Gọi chatbot API remote (CHATBOT_API_BASE from config.py) → lấy câu trả lời
 2. judge: Codex (gpt-5.3-codex) đánh giá câu trả lời + verify bằng data thật
 3. optimize: Gemini phân tích lỗi → sinh prompt mới
 """
@@ -53,7 +53,7 @@ class OptimizeRequest(BaseModel):
 @router.post("/run-test", summary="Run a test case through the remote chatbot")
 async def run_test(req: RunTestRequest):
     """
-    Call chatbot API tại 172.16.2.207:5000/api/agent/chat-dev
+    Call chatbot API tại CHATBOT_API_BASE/api/agent/chat-dev
     Lấy câu trả lời thật từ bot (dùng prompt Langfuse hiện tại).
     """
     try:

backend/common/sqlite_db.py

@@ -18,9 +18,8 @@ class SQLiteDBManager:
     def __new__(cls):
         if cls._instance is None:
             cls._instance = super(SQLiteDBManager, cls).__new__(cls)
-            # Default path trỏ thẳng vào: backend/database/canifa_ai_dump.sqlite
-            base_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-            cls._instance._db_path = os.path.join(base_dir, "database", "canifa_ai_dump.sqlite")
+            from common.constants import SQLITE_DB_PATH
+            cls._instance._db_path = SQLITE_DB_PATH
         return cls._instance
 
     @property

backend/config.py

@@ -170,3 +170,8 @@ LANGFUSE_SELF_HOSTED_URL: str = os.getenv("LANGFUSE_SELF_HOSTED_URL", "http://17
 N8N_BASE_URL: str = os.getenv("N8N_BASE_URL", "http://172.16.2.207:5678")
 LITELLM_BASE_URL: str = os.getenv("LITELLM_BASE_URL", "http://172.16.2.210:3002")
 STARROCKS_INGEST_HOST: str = os.getenv("STARROCKS_INGEST_HOST", "172.16.2.100")
+
+# ====================== INTERNAL API KEYS ======================
+FREE_LLM_API_KEY: str = os.getenv("FREE_LLM_API_KEY", "freellmapi-a858c30561987b8aa2a58343c7fe48a6a52e65cadb9df6d5")
+LANGFUSE_PUBLIC_KEY: str = os.getenv("LANGFUSE_PUBLIC_KEY", "pk-lf-2bb249b1-77e3-4309-8954-312b8fb2fff9")
+LANGFUSE_SECRET_KEY: str = os.getenv("LANGFUSE_SECRET_KEY", "sk-lf-bd0c7202-a7f4-4399-a36e-65ebe2e35104")

backend/tests/conftest.py

+"""
+conftest.py — Shared test configuration.
+
+Tất cả test files nên import BASE_URL từ đây thay vì hardcode.
+"""
+
+import os
+
+BASE_URL = os.getenv("TEST_BASE_URL", "http://localhost:5000")