style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/core/environment.py

@@ -15,7 +15,7 @@ EnvironmentType = Literal["development", "staging", "production"]
 def get_environment() -> EnvironmentType:
     """
     Detect current environment automatically.
-    
+
     Detection logic:
     1. Check ENV environment variable if set
     2. Check ENVIRONMENT environment variable if set
@@ -23,7 +23,7 @@ def get_environment() -> EnvironmentType:
        - localhost, 127.0.0.1 → development
        - Contains 'staging' → staging
        - Otherwise → production (safe default)
-    
+
     Returns:
         str: 'development', 'staging', or 'production'
     """
@@ -35,7 +35,7 @@ def get_environment() -> EnvironmentType:
         return "staging"
     elif env in ["production", "prod"]:
         return "production"
-    
+
     # Priority 2: ENVIRONMENT variable
     env = os.getenv("ENVIRONMENT", "").lower()
     if env in ["development", "dev", "local"]:
@@ -44,22 +44,25 @@ def get_environment() -> EnvironmentType:
         return "staging"
     elif env in ["production", "prod"]:
         return "production"
-    
+
     # Priority 3: Auto-detect from common indicators
-    
+
     # Check if running in debug mode (common in development)
     if os.getenv("DEBUG", "").lower() in ["true", "1", "yes"]:
         return "development"
-    
+
     # Check common development indicators
     hostname = os.getenv("HOSTNAME", "").lower()
-    if any(dev_indicator in hostname for dev_indicator in ["local", "dev", "laptop", "desktop"]):
+    if any(
+        dev_indicator in hostname
+        for dev_indicator in ["local", "dev", "laptop", "desktop"]
+    ):
         return "development"
-    
+
     # Check for staging indicators
     if "staging" in hostname or "stage" in hostname:
         return "staging"
-    
+
     # Default to development for safety (HTTPS not required in dev)
     # Change this to "production" if you prefer secure-by-default
     return "development"
@@ -83,7 +86,7 @@ def is_production() -> bool:
 def should_use_secure_cookies() -> bool:
     """
     Determine if cookies should have secure flag (HTTPS only).
-    
+
     Returns:
         bool: True if production or staging, False if development
     """
@@ -97,7 +100,7 @@ _cached_environment: EnvironmentType | None = None
 def get_cached_environment() -> EnvironmentType:
     """
     Get environment with caching.
-    
+
     Environment is detected once and cached for performance.
     Useful if you call this frequently.
     """