chore: add base config and package structure

app/__init__.py

@@ -1,8 +1,12 @@
 from flask import Flask
 
+from app.config import BaseConfig, load_config_from_env
+
 
 def create_app(config_object=None):
     app = Flask(__name__)
+    app.config.from_object(BaseConfig)
+    app.config.update(load_config_from_env())
 
     if config_object:
         if isinstance(config_object, dict):

app/chis/__init__.py

@@ -0,0 +1 @@
+"""CHIS integration layer."""

app/config.py

@@ -1,2 +1,16 @@
+import os
+
+
 class BaseConfig:
     JSON_AS_ASCII = False
+
+
+def load_config_from_env(environ=None):
+    source = environ or os.environ
+    return {
+        "CHIS_BASE_URL": source.get("CHIS_BASE_URL", ""),
+        "CHIS_PUBLIC_KEY": source.get("CHIS_PUBLIC_KEY", ""),
+        "REDIS_URL": source.get("REDIS_URL", "redis://localhost:6379/0"),
+        "LOG_DIR": source.get("LOG_DIR", "logs"),
+        "ARCHIVE_DIR": source.get("ARCHIVE_DIR", "archives"),
+    }

app/mappers/__init__.py

@@ -0,0 +1 @@
+"""Data mapping layer."""

app/middleware/__init__.py

@@ -0,0 +1 @@
+"""Request middleware helpers."""

app/repositories/__init__.py

@@ -0,0 +1 @@
+"""Persistence and cache repositories."""

app/services/__init__.py

@@ -0,0 +1 @@
+"""Application service layer."""

app/validators/__init__.py

@@ -0,0 +1 @@
+"""Request validators."""