Phase 1: pytest baseline, production hardening, pinned requirements

Establishes the safety net required before any structural refactor.

Tests (tests/):
- conftest.py rewritten for Flask-SQLAlchemy 3.x (drop-recreate per
  test, StaticPool-shared in-memory SQLite, admin_user + auth_headers
  fixtures). Removes deprecated db.create_scoped_session pattern.
- test_smoke.py: 8 baseline tests (app boot, JWT login valid+invalid,
  protected routes, paginated response shape, plugin auto-discovery).
- test_security_config.py: 7 tests pinning ProductionConfig.validate
  failure modes (missing/dev SECRET_KEY, missing JWT_SECRET_KEY,
  missing DATABASE_URL, wildcard CORS, empty CORS) and one happy-path.

Production hardening (shopdb/config.py, shopdb/__init__.py):
- ProductionConfig.validate() raises ConfigError on missing or
  insecure SECRET_KEY, JWT_SECRET_KEY, DATABASE_URL, CORS_ORIGINS.
  No silent fallback to dev defaults in production.
- create_app invokes validate() when config_name == 'production'.
- CORS_ORIGINS default no longer wildcard; defaults to localhost
  Vite dev origin.
- Drop os.path.exists probe in serve_frontend (path-traversal risk
  surface). send_from_directory handles safe-join + 404 itself.
- Replace User.query.get with db.session.get (SQLAlchemy 2.0 API).

TestingConfig (shopdb/config.py):
- Add StaticPool + check_same_thread connect_args so SQLite in-memory
  is shared across the test session.

Index dedup (plugins/printers/models/printer_extension.py):
- Rename idx_printer_windowsname -> idx_printerdata_windowsname.
  Two model classes (Printer, PrinterData) declared the same index
  name; SQLite enforces global index uniqueness even across tables.
  Per CONTRIBUTING.md naming convention, indexes follow
  idx_<table>_<column>.

Dependency pinning (requirements.in, requirements.txt):
- requirements.in holds the loose source pins (the human-edited file).
- requirements.txt is now a uv-compiled lockfile (every transitive
  dep pinned to an exact version). Reproducible builds. Run
  `uv pip compile requirements.in -o requirements.txt` to refresh.

Test count: 0 -> 15 passing. All naming/style checks still green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

shopdb/config.py

@@ -3,17 +3,33 @@
 import os
 from datetime import timedelta
 
+from sqlalchemy.pool import StaticPool
+
+
+class ConfigError(Exception):
+    """Raised when required configuration is missing or unsafe."""
+
+
+def _required_env(varname):
+    """Read an env var; raise ConfigError if missing or empty."""
+    value = os.environ.get(varname)
+    if not value:
+        raise ConfigError(
+            f'{varname} is required in production. Set it in the environment '
+            f'before starting the app. Insecure defaults are not permitted in '
+            f'ProductionConfig.'
+        )
+    return value
+
 
 class Config:
     """Base configuration."""
 
-    # Flask
     SECRET_KEY = os.environ.get('SECRET_KEY', 'dev-secret-key-change-in-production')
 
-    # SQLAlchemy
     SQLALCHEMY_DATABASE_URI = os.environ.get(
         'DATABASE_URL',
-        'mysql+pymysql://root:password@localhost:3306/shopdb_flask'
+        'mysql+pymysql://root:password@localhost:3306/shopdb_flask',
     )
     SQLALCHEMY_TRACK_MODIFICATIONS = False
     SQLALCHEMY_ENGINE_OPTIONS = {
@@ -21,7 +37,6 @@ class Config:
         'pool_recycle': 300,
     }
 
-    # JWT
     JWT_SECRET_KEY = os.environ.get('JWT_SECRET_KEY', 'jwt-secret-key-change-in-production')
     JWT_ACCESS_TOKEN_EXPIRES = timedelta(
         seconds=int(os.environ.get('JWT_ACCESS_TOKEN_EXPIRES', 3600))
@@ -30,21 +45,20 @@ class Config:
         seconds=int(os.environ.get('JWT_REFRESH_TOKEN_EXPIRES', 2592000))
     )
 
-    # CORS
-    CORS_ORIGINS = os.environ.get('CORS_ORIGINS', '*').split(',')
+    CORS_ORIGINS = [
+        origin.strip()
+        for origin in os.environ.get('CORS_ORIGINS', 'http://localhost:5173').split(',')
+        if origin.strip()
+    ]
 
-    # Logging
     LOG_LEVEL = os.environ.get('LOG_LEVEL', 'INFO')
 
-    # Zabbix
     ZABBIX_URL = os.environ.get('ZABBIX_URL', '')
     ZABBIX_TOKEN = os.environ.get('ZABBIX_TOKEN', '')
 
-    # Cache
     CACHE_TYPE = 'SimpleCache'
-    CACHE_DEFAULT_TIMEOUT = 600  # 10 minutes
+    CACHE_DEFAULT_TIMEOUT = 600
 
-    # Pagination
     DEFAULT_PAGE_SIZE = 20
     MAX_PAGE_SIZE = 100
 
@@ -55,12 +69,10 @@ class DevelopmentConfig(Config):
     DEBUG = True
     SQLALCHEMY_ECHO = True
 
-    # Use MySQL from DATABASE_URL
     SQLALCHEMY_DATABASE_URI = os.environ.get(
         'DATABASE_URL',
-        'mysql+pymysql://root:rootpassword@127.0.0.1:3306/shopdb_flask'
+        'mysql+pymysql://root:rootpassword@127.0.0.1:3306/shopdb_flask',
     )
-    # Keep pool options from base Config for MySQL
 
 
 class TestingConfig(Config):
@@ -68,23 +80,70 @@ class TestingConfig(Config):
 
     TESTING = True
     SQLALCHEMY_DATABASE_URI = 'sqlite:///:memory:'
+    SQLALCHEMY_ENGINE_OPTIONS = {
+        'connect_args': {'check_same_thread': False},
+        'poolclass': StaticPool,
+    }
     JWT_ACCESS_TOKEN_EXPIRES = timedelta(seconds=5)
 
 
 class ProductionConfig(Config):
-    """Production configuration."""
+    """Production configuration.
+
+    Validation is deferred to validate() so that importing this class in a
+    non-production environment (tests, dev, tooling) does not raise.
+    create_app() invokes validate() when config_name == 'production' so
+    a misconfigured production deploy still fails loud at boot.
+    """
 
     DEBUG = False
     SQLALCHEMY_ECHO = False
 
-    # Stricter security in production
     JWT_COOKIE_SECURE = True
     JWT_COOKIE_CSRF_PROTECT = True
 
+    @classmethod
+    def validate(cls):
+        """Verify production config is safe. Called from create_app."""
+        secret_key = os.environ.get('SECRET_KEY', '')
+        jwt_secret = os.environ.get('JWT_SECRET_KEY', '')
+        database_url = os.environ.get('DATABASE_URL', '')
+        cors_raw = os.environ.get('CORS_ORIGINS', '').strip()
+
+        insecure_defaults = {
+            'dev-secret-key-change-in-production',
+            'jwt-secret-key-change-in-production',
+        }
+
+        if not secret_key or secret_key in insecure_defaults:
+            raise ConfigError(
+                'SECRET_KEY is required in production and must not be the '
+                'development default. Set a strong random value in the '
+                'environment before starting the app.'
+            )
+        if not jwt_secret or jwt_secret in insecure_defaults:
+            raise ConfigError(
+                'JWT_SECRET_KEY is required in production and must not be '
+                'the development default. Set a strong random value in the '
+                'environment before starting the app.'
+            )
+        if not database_url:
+            raise ConfigError(
+                'DATABASE_URL is required in production. No fallback to a '
+                'development localhost URL is permitted.'
+            )
+        if not cors_raw or cors_raw == '*':
+            raise ConfigError(
+                'CORS_ORIGINS must be a comma-separated allowlist of '
+                'explicit origins in production. Wildcard "*" is not '
+                'permitted. Example: '
+                'CORS_ORIGINS=https://shopdb.example.com,https://shopdb-mirror.example.com'
+            )
+
 
 config = {
     'development': DevelopmentConfig,
     'testing': TestingConfig,
     'production': ProductionConfig,
-    'default': DevelopmentConfig
+    'default': DevelopmentConfig,
 }