Add app scaffold and workflows

app/backend/core/config.py

@@ -0,0 +1,49 @@
+"""Environment configuration derived from environment variables."""
+
+from functools import lru_cache
+from pydantic import SecretStr # Import SecretStr for sensitive data
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+class Settings(BaseSettings):
+    """
+    Application settings class using Pydantic BaseSettings.
+    Settings are loaded from environment variables and have default values defined here.
+    """
+
+    service_name: str = "avaaz-backend" # A unique functional identifier for the microservice
+    environment: str = "development" # Defines the current deployment stage (e.g., 'development', 'staging', 'production')
+
+    title: str = "Avaaz Language Tutoring API"
+    description: str = """
+        # Avaaz Language Tutoring API
+
+        This API powers the **avaaz.ai** mobile and web applications, providing the robust backend services for our AI-driven oral language skills tutor. The platform is specifically engineered to help students achieve oral proficiency using adaptive, conversational AI agents.
+
+        ## Key Services Provided:
+        *   **Conversational AI Engine:** Facilitates ultra-low-latency speech-to-speech interaction and provides instant corrective feedback (grammar, pronunciation, fluency).
+        *   **Curriculum Management:** Delivers structured, CEFR aligned lessons and scenarios focused on real-life immigrant contexts (healthcare, workplace, school).
+        *   **Assessment & Gamification:** Manages progress tracking, mock oral exam simulations, performance summaries, and motivational mechanics (streaks, badges).
+        *   **Cross-Platform Sync:** Ensures seamless learning continuity and progress synchronization across all user devices.
+        """
+    
+    version: str = "0.1.0" # The current semantic version of the API application
+    
+    # Use SecretStr to prevent accidental logging of credentials.
+    # Access the actual value using settings.database_url.get_secret_value()
+    database_url: SecretStr = SecretStr("postgresql+psycopg://postgres:postgres@postgres:5432/avaaz")
+
+    model_config = SettingsConfigDict(
+        env_prefix="",  # Load variables without a specific prefix (e.g., `DATABASE_URL` instead of `APP_DATABASE_URL`)
+        case_sensitive=False # Environment variable names are treated as case-insensitive during loading
+    )
+
+@lru_cache(maxsize=1)
+def get_settings() -> Settings:
+    """
+    Return a cached singleton instance of the application settings.
+    
+    This function leverages functools.lru_cache to ensure that environment variables
+    are read only once during the application's lifecycle, improving performance
+    and ensuring consistency across requests.
+    """
+    return Settings()